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: printer.rb
    path of file: ./repos/graphql-ruby/lib/graphql/schema
    
    the code of the file until where you have to start completion: # frozen_string_literal: true
module GraphQL
  class Schema
    # Used to convert your {GraphQL::Schema} to a GraphQL schema string
    #
    # @example print your schema to standard output (via helper)
    #   puts GraphQL
    
      def self.print_introspection_schema
        query_root = Class.new(GraphQL::Schema::Object) do
          graphql_name "Root"
          field :throwaway_field, String
          def self.visible?(ctx)
            false
          end
        end
        schema = Class.new(GraphQL::Schema) {
          query(query_root)
          def self.visible?(member, _ctx)
            member.graphql_name != "Root"
          end
        }

        introspection_schema_ast = GraphQL::Language::DocumentFromSchemaDefinition.new(
          schema,
          include_introspection_types: true,
          include_built_in_directives: true,
        ).document

        introspection_schema_ast.to_query_string(printer: IntrospectionPrinter.new)
      end