Executes the command.

def execute(self):
        """
        Executes the command.
        """
        from vsgen.util.logger import VSGLogger

        VSGLogger.info(self._logname, self._message)
        start = time.clock()
        for i in self._registerables:
            i.register()
        end = time.clock()
        VSGLogger.info(self._logname, "Register %s items in %s seconds:", len(self._registerables), end - start)
        self._start = time.clock()