class_docstr: Type dispatch table implementation.
  
  A type dispatch table is a list, L, of target types. Given a request type, R,
  the table selects a target type, T, according to the following dispatch rules:
    1. R == T or R is supertype of T (functions are contravariant on args)
    2. There does not exist O in L such that R is supertype of O and O is a
       supertype of T (in other words, T is the closest to R, within list L).
    3. If the above two rules are satisfied by multiple targets, the earliest
       inserted one is chosen.
docstr: Returns an iterable to all targets in the table.
code: def targets(self) -> Iterable[function_type.FunctionType]:
      """Returns an iterable to all targets in the table."""
      return self._dispatch_table.keys()
  
file_path: tensorflow-upstream/tensorflow/core/function/polymorphism/type_dispatch.py
imports: import collections
  from typing import Optional, Iterable
  from tensorflow.core.function.polymorphism import function_type
label_desc: Use image node_id 3 for calling the TypeDispatchTable obj's underlying member method code with example usage: obj.targets() and returns: self