code: def generate_return_type_declarations(
      overloads: Sequence[PythonSignatureNativeFunctionPair],
  ) -> List[str]:
      """
      Generate block of function declarations in `python_return_types.h` to initialize
      and return named tuple for a native function.
      """
      typenames: Dict[
          str, str
      ] = {}  # map from unique name + field name lists to typedef name
      declarations: List[
          str
      ] = []  # function declaration to register the typedef
  
      for overload in overloads:
          fieldnames = namedtuple_fieldnames(
              overload.function.func.returns
          )
          if not fieldnames:
              continue
  
          name = cpp.name(
              overload.function.func
          )  # use @with_native_function?
          tn_key = gen_namedtuple_typename_key(overload.function)
          typename = typenames.get(tn_key)
  
          if typename is None:
              typename = f'{name}NamedTuple{"" if not declarations else len(declarations)}'
              typenames[tn_key] = typename
              declarations.append(
                  f"PyTypeObject* get_{name}_namedtuple();"
              )
  
      return declarations
  
imports: import itertools
  import re
  from collections import defaultdict
  from typing import Callable, Dict, Iterable, List, Optional, Sequence, Set, Tuple
  import yaml
  from torchgen.api import cpp
  from torchgen.api.python import arg_parser_output_exprs, cpp_dispatch_exprs, cpp_dispatch_target, dispatch_lambda_args, dispatch_lambda_exprs, dispatch_lambda_return_str, has_tensor_options, namedtuple_fieldnames, PythonSignature, PythonSignatureDeprecated, PythonSignatureGroup, PythonSignatureNativeFunctionPair, signature, signature_from_schema
  from torchgen.code_template import CodeTemplate
  from torchgen.context import with_native_function
  from torchgen.gen import cpp_string, parse_native_yaml, parse_tags_yaml
  from torchgen.model import Argument, BaseOperatorName, FunctionSchema, NativeFunction, Type, Variant
  from torchgen.utils import FileManager, split_name_params
  from torchgen.yaml_utils import YamlLoader
  from .gen_trace_type import should_trace
label_desc: Use image node_id 23 for calling a global function with example usage: generate_return_type_declarations(overloads) and returns: declarations