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: variables.rb
    path of file: ./repos/gitlabhq/lib/gitlab/graphql
    
    the code of the file until where you have to start completion: # frozen_string_literal: true

module Gitlab
  module Graphql
    class Variables
      Invalid = Class.new(Gitlab::Graphql::S
    
      def ensure_hash(ambiguous_param)
        case ambiguous_param
        when String
          if ambiguous_param.present?
            ensure_hash(Gitlab::Json.parse(ambiguous_param))
          else
            {}
          end