<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def next(self):
 """ Get the next child. @return: The next child. @rtype: L{Element} @raise StopIterator: At the end. """

        try:
            child = self.children[self.pos]
            self.pos += 1
            return child
        except:
            raise StopIteration()