docs: def append_offsetvector(self, offsetvect, process):
  		"""
  		Append rows describing an instrument --> offset mapping to
  		this table.  offsetvect is a dictionary mapping instrument
  		to offset.  process should be the row in the process table
  		on which the new time_slide table rows will be blamed (or
  		any object with a process_id attribute).  The return value
  		is the time_slide_id assigned to the new rows.
  		"""
  		time_slide_id = self.get_next_id()
  		for instrument, offset in offsetvect.items():
  			row = self.RowType()
  			row.process_id = process.process_id
  			row.time_slide_id = time_slide_id
  			row.instrument = instrument
  			row.offset = offset
  			self.append(row)
  		return time_slide_id