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: get_build_number.rb
    path of file: ./repos/fastlane/fastlane/lib/fastlane/actions
    
    the code of the file until where you have to start completion: module Fastlane
  module Actions
    module SharedValues
      BUILD_NUMBER ||= :BUILD_NUMBER # originally defined in IncrementBuildNumberAction
    end

    class GetBuildNumberAction < Action
      require 'shellwords'

      def self.run(params)
        # More information about how to set up your project and how it works:
        # https://developer.apple.com/library/ios/qa/qa1827/_index.html

      
    
      def self.run(params)
        # More information about how to set up your project and how it works:
        # https://developer.apple.com/library/ios/qa/qa1827/_index.html

        folder = params[:xcodeproj] ? File.join(params[:xcodeproj], '..') : '.'

        command_prefix = [
          'cd',
          File.expand_path(folder).shellescape,
          '&&'
        ].join(' ')

        command = [
          command_prefix,
          'agvtool',
          'what-version',
          '-terse'
        ].join(' ')

        if Helper.test?
          Actions.lane_context[SharedValues::BUILD_NUMBER] = command
        else
          build_number = Actions.sh(command).split("\n").last.strip

          # Store the number in the shared hash
          Actions.lane_context[SharedValues::BUILD_NUMBER] = build_number
        end