def METHOD_NAME(spiketrains):
    """
    Converts a list of spiketrains into spynnaker7 format.
    :param list(~neo.core.SpikeTrain) spiketrains: List of SpikeTrains
    :rtype: ~numpy.ndarray
    """
    if len(spiketrains) == 0:
        return np.empty(shape=(0, 2))
    neurons = np.concatenate([
        np.repeat(x.annotations['source_index'], len(x))
        for x in spiketrains])
    spikes = np.concatenate([x.magnitude for x in spiketrains])
    return np.column_stack((neurons, spikes))