code: def _print_union(type):
      return "union {} = {}".format(
          type.name, " | ".join(str(t) for t in type.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 13 for calling a global function with example usage: _print_union(type) and returns: str