code: def _split_what(what):
      """
      Returns a tuple of `frozenset`s of classes and attributes.
      """
      return (
          frozenset(cls for cls in what if isinstance(cls, type)),
          frozenset(cls for cls in what if isinstance(cls, str)),
          frozenset(cls for cls in what if isinstance(cls, Attribute)),
      )
  
imports: from ._make import Attribute
label_desc: Use image node_id 1 for calling a global function with example usage: _split_what(what) and returns: frozenset,  frozenset,  frozenset