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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 execute(self, command, params):
 """ Send a command to the remote server. Any path subtitutions required for the URL mapped to the command should be included in the command parameters. :Args: - command - A string specifying the command to execute. - params - A dictionary of named parameters to send with the command as its JSON payload. """

        command_info = self._commands[command]
        assert command_info is not None, 'Unrecognised command %s' % command
        path = string.Template(command_info[1]).substitute(params)
        if hasattr(self, 'w3c') and self.w3c and isinstance(params, dict) and 'sessionId' in params:
            del params['sessionId']
        data = utils.dump_json(params)
        url = '%s%s' % (self._url, path)
        return self._request(command_info[0], url, body=data)