code: def backout_last(self, updated_singles, num_coincs):
          
          for ifo in updated_singles:
              self.singles[ifo].discard_last(updated_singles[ifo])
          self.coincs.remove(num_coincs)
docs: 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