parameters: (self, field_name)
docstring: Clears the contents of a given field, or the field set inside a oneof
      group.  If the name neither refers to a defined field or oneof group,
      ValueError is raised.
docstring_summary: Clears the contents of a given field, or the field set inside a oneof
      group.  If the name neither refers to a defined field or oneof group,
      ValueError is raised.
docstring_tokens: Clears the contents of a given field or the field set inside a oneof group . If the name neither refers to a defined field or oneof group ValueError is raised .
function: def ClearField(self, field_name):
      """Clears the contents of a given field, or the field set inside a oneof
      group.  If the name neither refers to a defined field or oneof group,
      ValueError is raised."""
      raise NotImplementedError
function_tokens: def ClearField ( self , field_name ) : raise NotImplementedError