message: Minor speedup of the sequential model run eagerly
diff: @@ -103,6 +103,8 @@ class Sequential(Model):
  self._build_input_shape = None
  self._compute_output_and_mask_jointly = True
  + self._layer_call_argspecs = {}
  +
  # Add to the model any layers passed to the constructor.
  if layers:
  for layer in layers:
  @@ -192,6 +194,8 @@ class Sequential(Model):
  if self._layers:
  self._track_layers(self._layers)
  + self._layer_call_argspecs[layer] = tf_inspect.getfullargspec(layer.call)
  +
  @checkpointable.no_automatic_dependency_tracking
  def pop(self):
  """Removes the last layer in the model.
  @@ -202,7 +206,8 @@ class Sequential(Model):
  if not self.layers:
  raise TypeError('There are no layers in the model.')
  - self._layers.pop()
  + layer = self._layers.pop()
  + self._layer_call_argspecs.pop(layer)
  if not self.layers:
  self.outputs = None
  self.inputs = None
  @@ -240,9 +245,10 @@ class Sequential(Model):
  x = inputs
  for layer in self.layers:
  kwargs = {}
  - if 'mask' in tf_inspect.getfullargspec(layer.call).args:
  + argspec = self._layer_call_argspecs[layer].args
  + if 'mask' in argspec:
  kwargs['mask'] = mask
  - if 'training' in tf_inspect.getfullargspec(layer.call).args:
  + if 'training' in argspec:
  kwargs['training'] = training
  if isinstance(layer, Network) and layer._compute_output_and_mask_jointly:
  