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: google_credential.rb
    path of file: ./repos/manageiq/lib/ansible/runner/credential
    
    the code of the file until where you have to start completion: module Ansible
  class Runner
    class GoogleCredential < Credential
      def self.auth_type
        "ManageIQ::Providers::EmbeddedAnsible::AutomationManager::GoogleCredential"
      end

      # Modeled off of gce injectors for awx:
      #
      #   https://github.com/ansible/awx/blob/1242ee2b/awx/main/models/credential/injectors.py#L18-L42
      #
      def env_vars
        {
          "GCE_EMAIL"                 => auth.userid || "",
          "GCE_PROJECT"               => auth.project || "",
          "GCE_CREDENTIALS_FILE_PATH" => gce_credentials_file
    
    
      def write_gce_credentials_file
        json_data = {
          :type                        => "service_account",
          :private_key                 => auth.auth_key || "",
          :client_email                => auth.userid || "",
          :project_id                  => auth.project || "",
          :auth_uri                    => "https://accounts.google.com/o/oauth2/auth",
          :token_uri                   => "https://oauth2.googleapis.com/token",
          :auth_provider_x509_cert_url => "https://www.googleapis.com/oauth2/v1/certs"
        }

        if auth.userid.present?
          client_x509_cert_url = "https://www.googleapis.com/robot/v1/metadata/x509/#{CGI.escape(auth.userid)}"
          json_data[:client_x509_cert_url] = client_x509_cert_url
        end