code: def ptr_type(self) -> str:
      # don't include defaults in type signature!
      args_str = ", ".join(a.defn() for a in self.arguments())
      return f"{native.returns_type(self.func.returns, symint=self.symint).cpp_type()} (*)({args_str})"
  
imports: from dataclasses import dataclass
  from typing import Iterator, List, Optional, Sequence, Set, Tuple, Union
  from torchgen.model import BackendIndex, FunctionSchema, NativeFunction, NativeFunctionsGroup, NativeFunctionsViewGroup
  from .types_base import Binding, CType, Expr
  from torchgen.api import cpp, dispatcher, functionalization, native, structured, translate
label_desc: Use image node_id 4 for calling the NativeSignature obj's underlying member method code with example usage: obj.ptr_type() and returns: native, str, args_str, str