code: def emit_dispatch_case(
      overload: PythonSignatureGroup,
      namedtuple_typenames: Dict[str, str],
      *,
      symint: bool = True,
  ) -> str:
      """
      Emit dispatch code for a single parsed signature. This corresponds to either
      a single native function, or a pair that differ only in output params. In the
      latter case, a single python signature is used for both and dispatching
      switches on the presence/absence of passed output args.
      """
      if overload.outplace is not None:
          # dispatch output and no-output variants, branch on _r.isNone(<out_idx>)
          return PY_VARIABLE_OUT.substitute(
              out_idx=overload.signature.output_idx(),
              call_dispatch=emit_single_dispatch(
                  overload.signature,
                  overload.base,
                  namedtuple_typenames,
                  symint=symint,
              ),
              call_dispatch_out=emit_single_dispatch(
                  overload.signature,
                  overload.outplace,
                  namedtuple_typenames,
                  symint=symint,
              ),
          )
      else:
          # no-output version only
          return emit_single_dispatch(
              overload.signature,
              overload.base,
              namedtuple_typenames,
              symint=symint,
          )
  
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 26 for calling a global function with example usage: emit_dispatch_case(overload, namedtuple_typenames) and returns: PY_VARIABLE_OUT, emit_single_dispatch