<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def handle(self):
 """ Executes the actual Stratum program. """

        self.output = PyStratumStyle(self.input, self.output)

        command = self.get_application().find('constants')
        ret = command.execute(self.input, self.output)
        if ret:
            return ret

        command = self.get_application().find('loader')
        ret = command.execute(self.input, self.output)
        if ret:
            return ret

        command = self.get_application().find('wrapper')
        ret = command.execute(self.input, self.output)

        self.output.writeln('')

        return ret