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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def touch(self, filepath):
 """Touches the specified file so that its modified time changes."""

        if self.is_ssh(filepath):
            self._check_ssh()
            remotepath = self._get_remote(filepath)
            stdin, stdout, stderr = self.ssh.exec_command("touch {}".format(remotepath))
            stdin.close()
        else:
            os.system("touch {}".format(filepath))