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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 getElementById(self, node, id, default=join):
 """Return the first child of node matching an id reference."""

        attrget = self.getAttr
        ELEMENT_NODE = node.ELEMENT_NODE
        for child in node.childNodes:
            if child.nodeType == ELEMENT_NODE:
                if attrget(child, 'id') == id:
                    return child
        if default is not join:
            return default
        raise KeyError, name