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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 _spikes_in_clusters(spike_clusters, clusters):
 """Return the ids of all spikes belonging to the specified clusters."""

    if len(spike_clusters) == 0 or len(clusters) == 0:
        return np.array([], dtype=np.int)
    return np.nonzero(np.in1d(spike_clusters, clusters))[0]