144     def value(self, extra=None):  argument
156     def explanation(self, extra=None):  argument
376     def value(self, index, extra=None):  argument
478     def explanation(self, index, extra=None):  argument
503     def callback(self, symbol, extra):  argument
512     def value(self, index, extra=None):  argument
540     def value(self, index, extra):  argument
571     def value(self, index, extra):  argument
582     def explanation(self, index, extra):  argument
629     def explanation(self, index, extra=None):  argument
648     def explanation(self, index, extra):  argument
651     def value(self, index, extra):  argument
721     def value(self, index, extra):  argument
730     def explanation(self, index, extra):  argument
789     def value(self, index, extra):  argument
798     def explanation(self, index, extra):  argument
834     def explanation(self, index, extra):  argument
884     def explanation(self, index, extra):  argument
897     def value(self, index, extra):  argument
904     def explanation(self, index, extra):  argument
944     def explanation(self, index, extra):  argument
978     def value(self, index, extra):  argument
985     def explanation(self, index, extra):  argument
1008     def value(self, index, extra=None):  argument
1011     def explanation(self, index, extra=None):  argument
1091     def value(self, index, extra):  argument
1099     def explanation(self, index, extra):  argument
1190     def explanation(self, index, extra):  argument
1817         def distanceCallback(symbol, extra):  argument