def get_end_time(self):
        """
        returns end time of simulation
        """
        end_time = c_double()
        self.library.get_end_time.argtypes = [POINTER(c_double)]
        self.library.get_end_time.restype = None
        self.library.get_end_time(byref(end_time))
        return end_time.value
returns end time of simulation