code: def _find_table_group(h5file, ifo=None):
      
      exclude = ('background',)
      if ifo is None:
          try:
              ifo, = [key for key in h5file if key not in exclude]
          except ValueError as exc:
              exc.args = ("PyCBC live HDF5 file contains dataset groups "
                          "for multiple interferometers, please specify "
                          "the prefix of the relevant interferometer via "
                          "the `ifo` keyword argument, e.g: `ifo=G1`",)
              raise
      try:
          return h5file[ifo], ifo
      except KeyError as exc:
          exc.args = ("No group for ifo %r in PyCBC live HDF5 file" % ifo,)
          raise
docs: Find the right `h5py.Group` within the given `h5py.File`