class_docstr: Inspects a given class and collects information about its instance
  methods.
  
  Args:
      cls (Type): The class to inspect.
docstr: Returns the source code of :obj:`cls`.
docstr_tok: ["Returns","the","source","code","of",":","obj",":","`","cls","`","."]
code: def get_source(self, cls: Optional[Type] = None) -> str:
      r"""Returns the source code of :obj:`cls`."""
      cls = cls or self._cls
      if cls.__name__ in self._source_dict:
          return self._source_dict[cls.__name__]
      try:
          source = inspect.getsource(cls)
      except Exception:
          source = ""
      self._source_dict[cls.__name__] = source
      return source
  
imports: import inspect
  import re
  import sys
  import typing
  from typing import Any, Callable, Dict, List, NamedTuple, Optional, Type, Union
  from torch import Tensor
label_desc: Use image node_id 18 for calling the Inspector obj's underlying member method code with example usage: obj.get_source(cls) and returns: source, self