code: def get_abstract_impl(qualname):
      if qualname not in torch._custom_op.impl.global_registry:
          return None
      custom_op = torch._custom_op.impl.global_registry[qualname]
      if custom_op is None:
          return None
      if not custom_op._has_impl("abstract"):
          return None
      return custom_op._get_impl("abstract").func
  
imports: import dataclasses
  import functools
  import inspect
  import sys
  import typing
  import weakref
  from torchgen.model import FunctionSchema, OperatorName, SchemaKind, BaseType, ListType, BaseTy
  import torch
  import torch._C
  import torch.library
  from torch._library.abstract_impl import AbstractImplCtx
  from torch.library import get_ctx
  from .autograd import autograd_kernel_indirection, construct_autograd_kernel
label_desc: Use image node_id 18 for calling a global function with example usage: get_abstract_impl(qualname) and returns: custom_op, None, None, None