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: default_platform.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
      DEFAULT_PLATFORM = :DEFAULT_PLATFORM
    end

    class DefaultPlatformAction < Action
     
    
      def self.run(params)
        UI.user_error!("You forgot to pass the default platform") if params.first.nil?

        platform = params.first.to_sym

        SupportedPlatforms.verify!(platform)

        Actions.lane_context[SharedValues::DEFAULT_PLATFORM] = platform
      end