def delete_solitary_syncs(data):
"""
Delete all sync events that are followed directly by the next sync event,
i.e., are useless.
"""
if len(data) == 0:
return np.zeros((0, 3), dtype='u8')
t0 = time.time()
print '* delete solitary syncs... ',
idxs = T2_tools.delete_solitary_syncs(data)
data = np.delete(data, idxs, axis=0)
t1 = time.time() - t0
print 'done ({:.2f} s).'.format(t1)
return data
