def value(self, node):
     return Sequence.value(self, node)[0]
 def value(self, node):
     return Sequence.value(self, node)[0]
 def value(self, node):
     return self.delimiter.join(
         str(v) for v in Sequence.value(self, node) if v)
 def value(self, node):
     return self.delimiter.join(str(v)
                                for v in Sequence.value(self, node)
                                if v)