code: def to_array(self):
          
          array = super(ChatPhoto, self).to_array()
          array['small_file_id'] = u(self.small_file_id)  # py2: type unicode, py3: type str
  
          array['big_file_id'] = u(self.big_file_id)  # py2: type unicode, py3: type str
  
          return array
docs: Serializes this ChatPhoto to a dictionary.
  
          :return: dictionary representation of this object.
          :rtype: dict