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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def append(self):
 """Append a new item to the sequence, appending it to the end. @return: The newly created item. @raises L{WSDLParseError}: If the operation would result in having more child elements than the allowed max. """

        tag = self._schema.tag
        children = self._root.getchildren()
        if len(children) >= self._schema.max_occurs:
            raise WSDLParseError("Too many items in tag '%s'" % tag)
        schema = self._schema.child
        tag = "item"
        if self._namespace is not None:
            tag = "{%s}%s" % (self._namespace, tag)
        child = etree.SubElement(self._root, tag)
        return schema.create(child)