class_docstr: A CppSignature represents a single overload in the C++ API.  For
  any given function schema, there may be multiple CppSignatures
  corresponding to it, based on how we desugar to C++.  See also
  CppSignatureGroup.
class_docstr_tok: ["A","CppSignature","represents","a","single","overload","in","the","C++","API",".","For","any","given","function","schema",",","there","may","be","multiple","CppSignatures","corresponding","to","it",",","based","on","how","we","desugar","to","C++",".","See","also","CppSignatureGroup","."]
code: def defn(
      self,
      *,
      name: Optional[str] = None,
      prefix: str = "",
      is_redispatching_fn: bool = False,
  ) -> str:
      returns_type = cpp.returns_type(
          self.func.returns, symint=self.symint
      ).cpp_type()
      cpp_args = [a.defn() for a in self.arguments()]
      if is_redispatching_fn:
          cpp_args = ["c10::DispatchKeySet dispatchKeySet"] + cpp_args
      cpp_args_str = ", ".join(cpp_args)
      if name is None:
          name = prefix + self.name()
      return f"{returns_type} {name}({cpp_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 CppSignature obj's underlying member method code with example usage: obj.defn() and returns: returns_type, str, name, str, cpp_args_str, str