parameters: (self, name, default_value)
docstring: Create the attribute with the default value if it hasn't been created.
  
      This is useful for fields that is used for tracking purpose,
      _trainable_weights, or _layers. Note that user could create a layer subclass
      and assign an internal field before invoking the Layer.__init__(), the
      __setattr__() need to create the tracking fields and __init__() need to not
      override them.
  
      Args:
        name: String, the name of the attribute.
        default_value: Object, the default value of the attribute.
docstring_summary: Create the attribute with the default value if it hasn't been created.
docstring_tokens: Create the attribute with the default value if it hasn t been created .
function: def _maybe_create_attribute(self, name, default_value):
      """Create the attribute with the default value if it hasn't been created.
  
      This is useful for fields that is used for tracking purpose,
      _trainable_weights, or _layers. Note that user could create a layer subclass
      and assign an internal field before invoking the Layer.__init__(), the
      __setattr__() need to create the tracking fields and __init__() need to not
      override them.
  
      Args:
        name: String, the name of the attribute.
        default_value: Object, the default value of the attribute.
      """
      if not hasattr(self, name):
        self.__setattr__(name, default_value)
function_tokens: def _maybe_create_attribute ( self , name , default_value ) : if not hasattr ( self , name ) : self . __setattr__ ( name , default_value )