code: def set_gamma_value(self, value):
          '''
          setter
          Gamma value.
          '''
          if isinstance(value, float) is False:
              raise TypeError("The type of __gamma_value must be float.")
          self.__gamma_value = valuf set_gamma_value(self, value):
          '''
          setter
          Gamma value.
          '''
          if isinstance(value, float) is False:
              raise TypeError("The type of __gamma_value must be float.")
          self.__gamma_value = value
docs: setter
          Gamma value.