def convert_tree(self, element1, element2=None):
if element2 is None:<EOL><INDENT>attributes = deepcopy(element1.attrib)<EOL>tag = attributes['<STR_LIT:name>']<EOL>del attributes['<STR_LIT:name>']<EOL>element2 = etree.Element(tag, attributes)<EOL><DEDENT>for e1 in element1.findall('<STR_LIT>'):<EOL><INDENT>attributes = deepcopy(e1.attrib)<EOL>tag = self.prefix_to_url(attributes['<STR_LIT:name>'])<EOL>del attributes['<STR_LIT:name>']<EOL>e2 = etree.SubElement(element2, tag, attributes)<EOL>self.convert_tree(e1, e2)<EOL><DEDENT>return element2<EOL>
convert_tree

        High-level api: Convert cxml tree to an internal schema tree. This
        method is recursive.

        Parameters
        ----------

        element1 : `Element`
            The node to be converted.

        element2 : `Element`
            A new node being constructed.

        Returns
        -------

        Element
            This is element2 after convertion.