docs: def find(self, item):
  		"""
  		Return the smallest i such that i is the index of an
  		element that wholly contains item.  Raises ValueError if no
  		such element exists.  Does not require the segmentlist to
  		be coalesced.
  		"""
  		for i, seg in enumerate(self):
  			if item in seg:
  				return i
  		raise ValueError(item)