def backout_last(self, updated_singles, num_coincs):
        """Remove the recently added singles and coincs

        Parameters
        ----------
        updated_singles: dict of numpy.ndarrays
            Array of indices that have been just updated in the internal
            buffers of single detector triggers.
        num_coincs: int
            The number of coincs that were just added to the internal buffer
            of coincident triggers
        """
        for ifo in updated_singles:
            self.singles[ifo].discard_last(updated_singles[ifo])
        self.coincs.remove(num_coincs)