17 files changed, 5 insertions, 469 deletions
diff --git a/Rakefile b/Rakefile
index fcbf7b5866..1b08fdbfe9 100644
--- a/Rakefile
+++ b/Rakefile
@@ -328,13 +328,6 @@ begin
     lib.vendor_lib = "lib/bundler/vendor/thor"
   end
 
-  Automatiek::RakeTask.new("postit") do |lib|
-    lib.download = { :github => "https://github.com/bundler/postit" }
-    lib.namespace = "PostIt"
-    lib.prefix = "BundlerVendoredPostIt"
-    lib.vendor_lib = "lib/bundler/vendor/postit"
-  end
-
   Automatiek::RakeTask.new("net-http-persistent") do |lib|
     lib.download = { :github => "https://github.com/drbrain/net-http-persistent" }
     lib.namespace = "Net::HTTP::Persistent"
@@ -355,7 +348,6 @@ rescue LoadError
   namespace :vendor do
     task(:molinillo) { abort "Install the automatiek gem to be able to vendor gems." }
     task(:thor) { abort "Install the automatiek gem to be able to vendor gems." }
-    task(:postit) { abort "Install the automatiek gem to be able to vendor gems." }
     task("net-http-persistent") { abort "Install the automatiek gem to be able to vendor gems." }
   end
 end
diff --git a/doc/development/SETUP.md b/doc/development/SETUP.md
index 2011651252..d4ec555fef 100644
--- a/doc/development/SETUP.md
+++ b/doc/development/SETUP.md
@@ -20,9 +20,7 @@ Bundler doesn't use a Gemfile to list development dependencies, because when we
 
 4. Set up a shell alias to run Bundler from your clone, e.g. a Bash alias:
 
-      `$ alias dbundle='BUNDLE_TRAMPOLINE_DISABLE=1 ruby -I /path/to/bundler/lib /path/to/bundler/exe/bundle'`
-
-   The `BUNDLE_TRAMPOLINE_DISABLE` environment variable ensures that the version of Bundler in `/path/to/bundler/lib` will be used. Without that environment setting, Bundler will automatically download, install, and run the version of Bundler listed in `Gemfile.lock`. With that set up, you can test changes you've made to Bundler by running `dbundle`, without interfering with the regular `bundle` command.
+      `$ alias dbundle='ruby -I /path/to/bundler/lib /path/to/bundler/exe/bundle'`
 
 ## Debugging with `pry`
 
diff --git a/exe/bundle b/exe/bundle
index d73e9984c9..aaf773745d 100755
--- a/exe/bundle
+++ b/exe/bundle
@@ -7,11 +7,6 @@ Signal.trap("INT") do
   exit 1
 end
 
-update = "update".start_with?(ARGV.first || " ") && ARGV.find {|a| a.start_with?("--bundler") }
-update &&= update =~ /--bundler(?:=(.+))?/ && $1 || "> 0.a"
-ENV["BUNDLER_VERSION"] = update if update
-require "bundler/postit_trampoline"
-
 require "bundler"
 # Check if an older version of bundler is installed
 $LOAD_PATH.each do |path|
diff --git a/lib/bundler/cli.rb b/lib/bundler/cli.rb
index 58a7ce491a..c09b14433a 100644
--- a/lib/bundler/cli.rb
+++ b/lib/bundler/cli.rb
@@ -619,7 +619,7 @@ module Bundler
     end
 
     def print_command
-      return unless ENV["BUNDLE_POSTIT_TRAMPOLINING_VERSION"] || Bundler.ui.debug?
+      return unless Bundler.ui.debug?
       _, _, config = @_initializer
       current_command = config[:current_command]
       command_name = current_command.name
diff --git a/lib/bundler/cli/install.rb b/lib/bundler/cli/install.rb
index c110f516fc..0592385e23 100644
--- a/lib/bundler/cli/install.rb
+++ b/lib/bundler/cli/install.rb
@@ -13,8 +13,6 @@ module Bundler
 
       warn_if_root
 
-      warn_if_outdated
-
       [:with, :without].each do |option|
         if options[option]
           options[option] = options[option].join(":").tr(" ", ":").split(":")
@@ -116,20 +114,6 @@ module Bundler
         "application for all non-root users on this machine.", :wrap => true
     end
 
-    def warn_if_outdated
-      return if ENV["BUNDLE_POSTIT_TRAMPOLINING_VERSION"].nil?
-      installed_version = Gem::Version.new(ENV["BUNDLE_POSTIT_TRAMPOLINING_VERSION"].dup)
-      running_version = Gem::Version.new(Bundler::VERSION)
-      return if Gem::Requirement.new(installed_version).satisfied_by?(running_version)
-      if Bundler.settings[:warned_version].nil? || running_version > Gem::Version.new(Bundler.settings[:warned_version])
-        Bundler.settings[:warned_version] = running_version
-        Bundler.ui.warn "You're running Bundler #{installed_version} but this " \
-          "project uses #{running_version}. To update, run `bundle update " \
-          "--bundler`. You won't see this message again unless you upgrade " \
-          "to a newer version of Bundler.", :wrap => true
-      end
-    end
-
     def dependencies_count_for(definition)
       count = definition.dependencies.count
       "#{count} Gemfile #{count == 1 ? "dependency" : "dependencies"}"
diff --git a/lib/bundler/postit_trampoline.rb b/lib/bundler/postit_trampoline.rb
deleted file mode 100644
index 576ce2a274..0000000000
--- a/lib/bundler/postit_trampoline.rb
+++ /dev/null
@@ -1,73 +0,0 @@
-# frozen_string_literal: true
-
-module BundlerVendoredPostIt; end
-require "bundler/vendor/postit/lib/postit"
-require "rubygems"
-
-environment = BundlerVendoredPostIt::PostIt::Environment.new([])
-version = Gem::Requirement.new(environment.bundler_version)
-if version.requirements.size == 1 && version.requirements.first.first == "=" # version.exact?
-  if version.requirements.first.last.segments.first >= 2
-    ENV["BUNDLE_TRAMPOLINE_FORCE"] = "true"
-  end
-end
-
-if ENV["BUNDLE_TRAMPOLINE_FORCE"] && !ENV["BUNDLE_TRAMPOLINE_DISABLE"]
-  installed_version =
-    if defined?(Bundler::VERSION)
-      Bundler::VERSION
-    else
-      File.read(File.expand_path("../version.rb", __FILE__)) =~ /VERSION = "(.+)"/
-      $1
-    end
-  installed_version &&= Gem::Version.new(installed_version)
-
-  if !version.satisfied_by?(installed_version)
-    begin
-      installer = BundlerVendoredPostIt::PostIt::Installer.new(version)
-      unless installer.installed?
-        warn "Installing locked Bundler version #{version.to_s.gsub("= ", "")}..."
-        installer.install!
-      end
-    rescue => e
-      abort <<-EOS.strip
-Installing the inferred bundler version (#{version}) failed.
-If you'd like to update to the current bundler version (#{installed_version}) in this project, run `bundle update --bundler`.
-The error was: #{e}
-    EOS
-    end
-
-    if deleted_spec = Gem.loaded_specs.delete("bundler")
-      deleted_spec.full_require_paths.each {|path| $:.delete(path) }
-    else
-      $:.delete(File.expand_path("../..", __FILE__))
-    end
-    gem "bundler", version
-  else
-    begin
-      gem "bundler", version
-    rescue LoadError
-      $:.unshift(File.expand_path("../..", __FILE__))
-    end
-  end
-
-  running_version = begin
-    require "bundler/version"
-    Bundler::VERSION
-  rescue LoadError, NameError
-    nil
-  end
-
-  ENV["BUNDLE_POSTIT_TRAMPOLINING_VERSION"] = installed_version.to_s
-
-  if !Gem::Requirement.new(">= 1.13.pre".dup).satisfied_by?(Gem::Version.new(running_version)) && (ARGV.empty? || ARGV.any? {|a| %w[install i].include? a })
-    puts <<-WARN.strip
-You're running Bundler #{installed_version} but this project uses #{running_version}. To update, run `bundle update --bundler`.
-  WARN
-  end
-
-  if !Gem::Version.correct?(running_version.to_s) || !version.satisfied_by?(Gem::Version.create(running_version))
-    abort "The running bundler (#{running_version}) does not match the required `#{version}`"
-  end
-
-end # if ENV["BUNDLE_TRAMPOLINE_FORCE"] && !ENV["BUNDLE_TRAMPOLINE_DISABLE"]
diff --git a/lib/bundler/setup.rb b/lib/bundler/setup.rb
index eb816b9988..9aae6478cd 100644
--- a/lib/bundler/setup.rb
+++ b/lib/bundler/setup.rb
@@ -1,5 +1,4 @@
 # frozen_string_literal: true
-require "bundler/postit_trampoline"
 require "bundler/shared_helpers"
 
 if Bundler::SharedHelpers.in_bundle?
@@ -20,12 +19,9 @@ if Bundler::SharedHelpers.in_bundle?
     Bundler.setup
   end
 
-  unless ENV["BUNDLE_POSTIT_TRAMPOLINING_VERSION"]
-    # Add bundler to the load path after disabling system gems
-    # This is guaranteed to be done already if we've trampolined
-    bundler_lib = File.expand_path("../..", __FILE__)
-    $LOAD_PATH.unshift(bundler_lib) unless $LOAD_PATH.include?(bundler_lib)
-  end
+  # Add bundler to the load path after disabling system gems
+  bundler_lib = File.expand_path("../..", __FILE__)
+  $LOAD_PATH.unshift(bundler_lib) unless $LOAD_PATH.include?(bundler_lib)
 
   Bundler.ui = nil
 end
diff --git a/lib/bundler/vendor/postit/lib/postit.rb b/lib/bundler/vendor/postit/lib/postit.rb
deleted file mode 100644
index e07dfccac4..0000000000
--- a/lib/bundler/vendor/postit/lib/postit.rb
+++ /dev/null
@@ -1,15 +0,0 @@
-require 'bundler/vendor/postit/lib/postit/environment'
-require 'bundler/vendor/postit/lib/postit/installer'
-require 'bundler/vendor/postit/lib/postit/parser'
-require 'bundler/vendor/postit/lib/postit/version'
-require 'rubygems'
-
-module BundlerVendoredPostIt::PostIt
-  def self.setup
-    load File.expand_path('../postit/setup.rb', __FILE__)
-  end
-
-  def self.bundler_version
-    defined?(Bundler::VERSION) && Bundler::VERSION
-  end
-end
diff --git a/lib/bundler/vendor/postit/lib/postit/environment.rb b/lib/bundler/vendor/postit/lib/postit/environment.rb
deleted file mode 100644
index 0c27f2cd69..0000000000
--- a/lib/bundler/vendor/postit/lib/postit/environment.rb
+++ /dev/null
@@ -1,44 +0,0 @@
-require 'bundler/vendor/postit/lib/postit/parser'
-
-module BundlerVendoredPostIt::PostIt
-  class Environment
-    def initialize(argv)
-      @argv = argv
-    end
-
-    def env_var_version
-      ENV['BUNDLER_VERSION']
-    end
-
-    def cli_arg_version
-      return unless str = @argv.first
-      str = str.dup.force_encoding('BINARY') if str.respond_to?(:force_encoding)
-      if Gem::Version.correct?(str)
-        @argv.shift
-        str
-      end
-    end
-
-    def gemfile
-      ENV['BUNDLE_GEMFILE'] || 'Gemfile'
-    end
-
-    def lockfile
-      File.expand_path case File.basename(gemfile)
-                       when 'gems.rb' then gemfile.sub(/\.rb$/, gemfile)
-                       else "#{gemfile}.lock"
-                       end
-    end
-
-    def lockfile_version
-      BundlerVendoredPostIt::PostIt::Parser.new(lockfile).parse
-    end
-
-    def bundler_version
-      @bundler_version ||= begin
-        env_var_version || cli_arg_version ||
-          lockfile_version || "#{Gem::Requirement.default}.a"
-      end
-    end
-  end
-end
diff --git a/lib/bundler/vendor/postit/lib/postit/installer.rb b/lib/bundler/vendor/postit/lib/postit/installer.rb
deleted file mode 100644
index 5fa34b6938..0000000000
--- a/lib/bundler/vendor/postit/lib/postit/installer.rb
+++ /dev/null
@@ -1,28 +0,0 @@
-module BundlerVendoredPostIt::PostIt
-  class Installer
-    def initialize(bundler_version)
-      @bundler_version = bundler_version
-    end
-
-    def installed?
-      if Gem::Specification.respond_to?(:find_by_name)
-        !Gem::Specification.find_by_name('bundler', @bundler_version).nil?
-      else
-        requirement = Gem::Requirement.new(@bundler_version)
-        Gem.source_index.gems.values.any? do |s|
-          s.name == 'bundler' && requirement.satisfied_by?(s.version)
-        end
-      end
-    rescue LoadError
-      false
-    end
-
-    def install!
-      return if installed?
-      require 'rubygems/dependency_installer'
-      installer = Gem::DependencyInstaller.new
-      installer.install('bundler', @bundler_version)
-      installer.installed_gems
-    end
-  end
-end
diff --git a/lib/bundler/vendor/postit/lib/postit/parser.rb b/lib/bundler/vendor/postit/lib/postit/parser.rb
deleted file mode 100644
index 7b2eb72ff1..0000000000
--- a/lib/bundler/vendor/postit/lib/postit/parser.rb
+++ /dev/null
@@ -1,21 +0,0 @@
-require 'rubygems'
-
-module BundlerVendoredPostIt::PostIt
-  class Parser
-    def initialize(file)
-      @file = file
-    end
-
-    BUNDLED_WITH =
-      /\n\nBUNDLED WITH\n\s{2,}(#{Gem::Version::VERSION_PATTERN})\n/
-
-    def parse
-      return unless lockfile = File.file?(@file) && File.read(@file)
-      if lockfile =~ BUNDLED_WITH
-        Regexp.last_match(1)
-      else
-        '< 1.10'
-      end
-    end
-  end
-end
diff --git a/lib/bundler/vendor/postit/lib/postit/setup.rb b/lib/bundler/vendor/postit/lib/postit/setup.rb
deleted file mode 100644
index 2580e7b7b8..0000000000
--- a/lib/bundler/vendor/postit/lib/postit/setup.rb
+++ /dev/null
@@ -1,12 +0,0 @@
-require 'bundler/vendor/postit/lib/postit/environment'
-require 'bundler/vendor/postit/lib/postit/installer'
-
-environment = BundlerVendoredPostIt::PostIt::Environment.new(ARGV)
-version = environment.bundler_version
-
-installer = BundlerVendoredPostIt::PostIt::Installer.new(version)
-installer.install!
-
-gem 'bundler', version
-
-require 'bundler/version'
diff --git a/lib/bundler/vendor/postit/lib/postit/version.rb b/lib/bundler/vendor/postit/lib/postit/version.rb
deleted file mode 100644
index b54175254d..0000000000
--- a/lib/bundler/vendor/postit/lib/postit/version.rb
+++ /dev/null
@@ -1,3 +0,0 @@
-module BundlerVendoredPostIt::PostIt
-  VERSION = '0.2.0'.freeze
-end
diff --git a/man/bundle.ronn b/man/bundle.ronn
index 9e42e046a7..c0726c9dcd 100644
--- a/man/bundle.ronn
+++ b/man/bundle.ronn
@@ -97,24 +97,6 @@ When running a command that isn't listed in PRIMARY COMMANDS or UTILITIES,
 Bundler will try to find an executable on your path named `bundler-<command>`
 and execute it, passing down any extra arguments to it.
 
-## BUNDLER TRAMPOLINING
-
-Bundler includes a feature called trampolining, designed to allow a single
-developer to work on multiple projects, each on different Bundler versions.
-The trampoline will infer the correct version of Bundler to use for each project
-and load that version instead of the version directly invoked (which is almost
-always the newest version installed locally).
-
-Bundler by default will use the Bundler version in the current directory to
-determine the version to trampoline to, reading from the `BUNDLED WITH` section.
-However, if the `BUNDLER_VERSION` environment variable is set, that version will
-override the lockfile inference and can be used in directories without a
-lockfile.
-
-Until the target version is Bundler 2 or later, `BUNDLE_TRAMPOLINE_FORCE` must
-be set for the trampoline to be used. Additionally, `BUNDLE_TRAMPOLINE_DISABLE` can
-be set to completely disable the trampoline.
-
 ## OBSOLETE
 
 These commands are obsolete and should no longer be used
diff --git a/spec/commands/install_spec.rb b/spec/commands/install_spec.rb
index 4ca8330d02..3b339e5147 100644
--- a/spec/commands/install_spec.rb
+++ b/spec/commands/install_spec.rb
@@ -484,25 +484,4 @@ RSpec.describe "bundle install with gem sources" do
                         "setting them for authentication.")
     end
   end
-
-  describe "warns user if Bundler is outdated" do
-    it "warns only once and is > 1.13.0.rc.1" do
-      gemfile <<-G
-        source "file://#{gem_repo1}"
-      G
-
-      bundle :install, :env => { "BUNDLE_POSTIT_TRAMPOLINING_VERSION" => "999" }
-      expect(out).to include("You're running Bundler 999 but this project uses #{Bundler::VERSION}.")
-
-      bundle :install, :env => { "BUNDLE_POSTIT_TRAMPOLINING_VERSION" => "999" }
-      expect(out).not_to include("You're running Bundler 999 but this project uses #{Bundler::VERSION}.")
-    end
-
-    it "should not print warning if versions match" do
-      bundle :init
-      bundle :install, :env => { "BUNDLE_POSTIT_TRAMPOLINING_VERSION" => Bundler::VERSION }
-      expect(out).to start_with("Running `bundle install --no-color` with bundler #{Bundler::VERSION}\nThe Gemfile specifies no dependencies")
-      expect(out).not_to include("You're running Bundler #{Bundler::VERSION} but this project uses #{Bundler::VERSION}.")
-    end
-  end
 end
diff --git a/spec/other/trampoline_spec.rb b/spec/other/trampoline_spec.rb
deleted file mode 100644
index 0ac9ee06a8..0000000000
--- a/spec/other/trampoline_spec.rb
+++ /dev/null
@@ -1,193 +0,0 @@
-# frozen_string_literal: true
-
-RSpec.describe "bundler version trampolining" do
-  before do
-    ENV["BUNDLE_TRAMPOLINE_DISABLE"] = nil
-    ENV["BUNDLE_TRAMPOLINE_FORCE"] = "true"
-    FileUtils.rm_rf(system_gem_path)
-    FileUtils.cp_r(base_system_gems, system_gem_path)
-  end
-
-  context "version guessing" do
-    shared_examples_for "guesses" do |version|
-      it "guesses the correct bundler version" do
-        bundle! "--version"
-        expect(out).to eq("Bundler version #{version}")
-
-        if bundled_app("Gemfile").file?
-          bundle! "exec ruby -e 'puts Bundler::VERSION'"
-          expect(out).to eq(version)
-        end
-      end
-    end
-
-    context "with a lockfile" do
-      before do
-        install_gemfile ""
-        lockfile lockfile.sub(Bundler::VERSION, "1.12.0")
-      end
-
-      include_examples "guesses", "1.12.0"
-    end
-
-    context "with BUNDLER_VERSION" do
-      before do
-        ENV["BUNDLER_VERSION"] = "1.12.0"
-      end
-
-      context "with a lockfile" do
-        before { install_gemfile "" }
-        include_examples "guesses", "1.12.0"
-      end
-
-      context "without a lockfile" do
-        include_examples "guesses", "1.12.0"
-      end
-    end
-
-    context "with no hints" do
-      include_examples "guesses", Bundler::VERSION
-    end
-
-    context "with a gemfile and no lockfile" do
-      before do
-        gemfile ""
-      end
-
-      include_examples "guesses", Bundler::VERSION
-    end
-  end
-
-  context "without BUNDLE_TRAMPOLINE_FORCE" do
-    before { ENV["BUNDLE_TRAMPOLINE_FORCE"] = nil }
-
-    context "when the version is >= 2" do
-      let(:version) { "2.7182818285" }
-      before do
-        simulate_bundler_version version do
-          install_gemfile! ""
-        end
-      end
-
-      it "trampolines automatically", :realworld => true do
-        bundle "--version"
-        expect(err).to include("Installing locked Bundler version #{version}...")
-      end
-    end
-  end
-
-  context "installing missing bundler versions", :realworld => true do
-    before do
-      ENV["BUNDLER_VERSION"] = "1.12.3"
-      if Bundler::RubygemsIntegration.provides?("< 2.6.4")
-        # necessary since we intall with 2.6.4 but the specs can run against
-        # older versions that match againt the "gem" invocation
-        %w[bundle bundler].each do |exe|
-          system_gem_path.join("bin", exe).open("a") do |f|
-            f << %(\ngem "bundler", ">= 0.a"\n)
-          end
-        end
-      end
-    end
-
-    it "guesses & installs the correct bundler version" do
-      expect(system_gem_path.join("gems", "bundler-1.12.3")).not_to exist
-      bundle! "--version"
-      expect(out).to eq("Bundler version 1.12.3")
-      expect(system_gem_path.join("gems", "bundler-1.12.3")).to exist
-    end
-
-    it "fails gracefully when installing the bundler fails" do
-      ENV["BUNDLER_VERSION"] = "9999"
-      bundle "--version"
-      expect(err).to start_with(<<-E.strip)
-Installing locked Bundler version 9999...
-Installing the inferred bundler version (= 9999) failed.
-If you'd like to update to the current bundler version (#{Bundler::VERSION}) in this project, run `bundle update --bundler`.
-The error was:
-      E
-    end
-
-    it "displays installing message before install is started" do
-      expect(system_gem_path.join("gems", "bundler-1.12.3")).not_to exist
-      bundle! "--version"
-      expect(err).to include("Installing locked Bundler version #{ENV["BUNDLER_VERSION"]}...")
-    end
-
-    it "doesn't display installing message if locked version is installed" do
-      expect(system_gem_path.join("gems", "bundler-1.12.3")).not_to exist
-      bundle! "--version"
-      expect(system_gem_path.join("gems", "bundler-1.12.3")).to exist
-      bundle! "--version"
-      expect(err).not_to include("Installing locked Bundler version = #{ENV["BUNDLER_VERSION"]}...")
-    end
-  end
-
-  context "bundle update --bundler" do
-    before do
-      simulate_bundler_version("1.11.1") do
-        install_gemfile ""
-      end
-    end
-
-    it "updates to the specified version" do
-      # HACK: since no released bundler version actually supports this feature!
-      bundle "update --bundler=1.12.0"
-      expect(out).to include("Unknown switches '--bundler=1.12.0'")
-    end
-
-    it "updates to the specified (running) version" do
-      # HACK: since no released bundler version actually supports this feature!
-      bundle! "update --bundler=#{Bundler::VERSION}"
-      bundle! "--version"
-      expect(out).to eq("Bundler version #{Bundler::VERSION}")
-    end
-
-    it "updates to the running version" do
-      # HACK: since no released bundler version actually supports this feature!
-      bundle! "update --bundler"
-      bundle! "--version"
-      expect(out).to eq("Bundler version #{Bundler::VERSION}")
-    end
-  end
-
-  context "-rbundler/setup" do
-    before do
-      simulate_bundler_version("1.12.0") do
-        install_gemfile ""
-      end
-    end
-
-    it "uses the locked version" do
-      ruby! <<-R
-        require "bundler/setup"
-        puts Bundler::VERSION
-      R
-      expect(err).to be_empty
-      expect(out).to include("1.12.0")
-    end
-  end
-
-  context "warnings" do
-    before do
-      simulate_bundler_version("1.12.0") do
-        install_gemfile ""
-      end
-    end
-
-    it "warns user if Bundler is outdated and is < 1.13.0.rc.1" do
-      ENV["BUNDLER_VERSION"] = "1.12.0"
-      bundle! "install"
-      expect(out).to include(<<-WARN.strip)
-You're running Bundler #{Bundler::VERSION} but this project uses #{ENV["BUNDLER_VERSION"]}. To update, run `bundle update --bundler`.
-      WARN
-    end
-  end
-
-  context "with --verbose" do
-    it "prints the running command" do
-      bundle! "config", :verbose => true, :env => { "BUNDLE_POSTIT_TRAMPOLINING_VERSION" => Bundler::VERSION }
-      expect(out).to start_with("Running `bundle config --verbose` with bundler #{Bundler::VERSION}")
-    end
-  end
-end
diff --git a/spec/support/helpers.rb b/spec/support/helpers.rb
index ffad652fc0..d961ad0886 100644
--- a/spec/support/helpers.rb
+++ b/spec/support/helpers.rb
@@ -12,7 +12,6 @@ module Spec
       end
       FileUtils.mkdir_p(home)
       FileUtils.mkdir_p(tmpdir)
-      ENV["BUNDLE_TRAMPOLINE_DISABLE"] = "1"
       Bundler.reset!
       Bundler.ui = nil
       Bundler.ui # force it to initialize