code: public List<Integer> getParameterIndexes(final int tid) {
          List<Integer> ret = termParameterIndex.get(tid);
          if (ret == null) {
              ret = emptyList();
          }
          return unmodifiableList(ret);
      }
docs: Returns the parameter indices for the provided term index.
  
  @param tid Term index
  @return The list of parameter indices, which may be empty