docs: def segmentlistdict(self):
  		"""
  		A segmentlistdict object describing the instruments and
  		time spanned by this CacheEntry.  A new object is
  		constructed each time this attribute is accessed (segments
  		are immutable so there is no reason to try to share a
  		reference to the CacheEntry's internal segment;
  		modifications of one would not be reflected in the other
  		anyway).
  
  		Example:
  
  		>>> c = CacheEntry(u"H1 S5 815901601 576.5 file://localhost/home/kipp/tmp/1/H1-815901601-576.xml")
  		>>> c.segmentlistdict
  		{u'H1': [segment(LIGOTimeGPS(815901601, 0), LIGOTimeGPS(815902177, 500000000))]}
  
  		The \"observatory\" column of the cache entry, which is
  		frequently used to store instrument names, is parsed into
  		instrument names for the dictionary keys using the same
  		rules as pycbc_glue.ligolw.lsctables.instrument_set_from_ifos().
  
  		Example:
  
  		>>> c = CacheEntry(u"H1H2, S5 815901601 576.5 file://localhost/home/kipp/tmp/1/H1H2-815901601-576.xml")
  		>>> c.segmentlistdict
  		{u'H1H2': [segment(LIGOTimeGPS(815901601, 0), LIGOTimeGPS(815902177, 500000000))]}
  		"""
  		# the import has to be done here to break the cyclic
  		# dependancy
  		from pycbc_glue.ligolw.lsctables import instrument_set_from_ifos
  		instruments = instrument_set_from_ifos(self.observatory) or (None,)
  		return segments.segmentlistdict((instrument, segments.segmentlist(self.segment is not None and [self.segment] or [])) for instrument in instruments)