You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: configurable.rb
    path of file: ./repos/gitlabhq/lib/gitlab/config/entry
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Gitlab
  module Config
    module Entry
      ##
      # This mixin is responsible for adding DSL, which
    
          def reserved_node_names
            self.nodes.select do |_, node|
              node.reserved?
            end.keys
          end

          private

          # rubocop: disable CodeReuse/ActiveRecord
          def entry(key, entry, description: nil, default: nil, inherit: nil, reserved: nil, deprecation: nil, metadata: {})
            entry_name = key.to_sym
            raise ArgumentError, "Entry '#{key}' already defined in '#{name}'" if @nodes.to_h[entry_name]

            factory = ::Gitlab::Config::Entry::Factory.new(entry)
              .with(description: description)
              .with(default: default)
              .with(inherit: inherit)
              .with(reserved: reserved)
              .with(deprecation: deprecation)
              .metadata(metadata)

            @nodes ||= {}
            @nodes[entry_name] = factory

            helpers(entry_name)
          end
          # rubocop: enable CodeReuse/ActiveRecord

          def dynamic_helpers(*nodes)
            helpers(*nodes, dynamic: true)
          end

          def helpers(*nodes, dynamic: false)
            nodes.each do |symbol|
              if method_defined?("#{symbol}_defined?") || method_defined?("#{symbol}_entry") || method_defined?("#{symbol}_value")
                raise ArgumentError, "Method '#{symbol}_defined?', '#{symbol}_entry' or '#{symbol}_value' already defined in '#{name}'"
              end

              unless @nodes.to_h[symbol]
                raise ArgumentError, "Entry for #{symbol} is undefined" unless dynamic
              end

              define_method("#{symbol}_defined?") do
                entries[symbol]&.specified?
              end

              define_method("#{symbol}_entry") do
                entries[symbol]
              end

              define_method("#{symbol}_value") do
                entry = entries[symbol]
                entry.value if entry&.valid?
              end
            end