code: def _signature_from_annotations(func):
      """Builds a dict mapping from parameter names to type annotations."""
      func_signature = tf_inspect.signature(func)
  
      signature = dict(
          [
              (name, param.annotation)
              for (name, param) in func_signature.parameters.items()
              if param.annotation != tf_inspect.Parameter.empty
          ]
      )
      if not signature:
          raise ValueError(
              "The dispatch_for_api decorator must be called with at "
              "least one signature, or applied to a function that "
              "has type annotations on its parameters."
          )
      return signature
  
imports: import collections
  import itertools
  import typing
  from tensorflow.python.framework import _pywrap_python_api_dispatcher
  from tensorflow.python.framework import ops
  from tensorflow.python.util import tf_decorator
  from tensorflow.python.util import tf_export
  from tensorflow.python.util import tf_inspect
  from tensorflow.python.util import traceback_utils
  from tensorflow.python.util import type_annotations
  from tensorflow.python.util.tf_export import tf_export
label_desc: Use image node_id 17 for calling a global function with example usage: _signature_from_annotations(func) and returns: signature