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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 connect(self):
        '''
        Connect to the drone.

        :raises RuntimeError: if the drone is connected or closed already.
        '''
        if self.connected:
            raise RuntimeError(
                '{} is connected already'.format(self.__class__.__name__))
        if self.closed:
            raise RuntimeError(
                '{} is closed already'.format(self.__class__.__name__))
        self.connected = True
        self._connect()