code: def _buildTerms(self):
          
          termLons = tables.termLons(tables.EGYPTIAN_TERMS)
          res = {}
          for (ID, sign, lon) in termLons:
              try:
                  res[sign][ID] = lon
              except KeyError:
                  res[sign] = {}
                  res[sign][ID] = lon
          return res
docs: Builds a data structure indexing the terms
          longitude by sign and object.