code: def _print_schema_definition(schema):
      operation_types = []
  
      query_type = schema.get_query_type()
      if query_type:
          operation_types.append("  query: {}".format(query_type))
  
      mutation_type = schema.get_mutation_type()
      if mutation_type:
          operation_types.append("  mutation: {}".format(mutation_type))
  
      subscription_type = schema.get_subscription_type()
      if subscription_type:
          operation_types.append(
              "  subscription: {}".format(subscription_type)
          )
  
      return "schema {{\n{}\n}}".format("\n".join(operation_types))
  
imports: from ..language.printer import print_ast
  from ..type.definition import GraphQLEnumType, GraphQLInputObjectType, GraphQLInterfaceType, GraphQLObjectType, GraphQLScalarType, GraphQLUnionType
  from ..type.directives import DEFAULT_DEPRECATION_REASON
  from .ast_from_value import ast_from_value
label_desc: Use image node_id 8 for calling a global function with example usage: _print_schema_definition(schema) and returns: str