code: def get_range_start_coord(self,rng):
      
      sys.stderr.write("error unimplemented get_range_start_coord\n")
      sys.exit()
      if rng.chr not in self._chrs: return None
      for l in [self._lines[x-1] for x in self._chrs[rng.chr]]:
        ####
        y = l['rng']
        c = y.cmp(rng)
        if c > 0: return None
        if c == 0:
          x = y.get_payload()
          return [x[1],x[2]] # don't need the name
      return None
docs: .. warning:: not implemented