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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 pcdata(self, tup_tree):
 """ Return the concatenated character data within the child nodes of a tuple tree node, as a unicode string. Whitespace is preserved. The child nodes must be text nodes (no element nodes). """

        try:
            data = u''.join(tup_tree[2])

        except TypeError:
            raise CIMXMLParseError(
                _format("Element {0!A} has unexpected child elements: "
                        "{1!A} (allowed is only text content)",
                        name(tup_tree), tup_tree[2]),
                conn_id=self.conn_id)

        return data