code: def get_gamma_value(self):
          '''
          getter
          Gamma value.
          '''
          if isinstance(self.__gamma_value, float) is False:
              raise TypeError("The type of __gamma_value must be float.")
          return self.__gamma_valuf get_gamma_value(self):
          '''
          getter
          Gamma value.
          '''
          if isinstance(self.__gamma_value, float) is False:
              raise TypeError("The type of __gamma_value must be float.")
          return self.__gamma_value
docs: getter
          Gamma value.