Setter for **self.__wait_time** attribute.

        :param value: Attribute value.
        :type value: int or float

def wait_time(self, value):
        """
        Setter for **self.__wait_time** attribute.

        :param value: Attribute value.
        :type value: int or float
        """

        if value is not None:
            assert type(value) in (int, float), "'{0}' attribute: '{1}' type is not 'int' or 'float'!".format(
                "wait_time", value)
            assert value >= 0, "'{0}' attribute: '{1}' need to be positive!".format("wait_time", value)
        self.__wait_time = value