def append_children(self, content):
        """
        Append child nodes into L{Content.data}
        @param content: The current content being unmarshalled.
        @type content: L{Content}
        """
        for child in content.node:
            cont = Content(child)
            cval = self.append(cont)
            key = reserved.get(child.name, child.name)
            if key in content.data:
                v = getattr(content.data, key)
                if isinstance(v, list):
                    v.append(cval)
                else:
                    setattr(content.data, key, [v, cval])
                continue
            if self.multi_occurrence(cont):
                if cval is None:
                    setattr(content.data, key, [])
                else:
                    setattr(content.data, key, [cval,])
            else:
                setattr(content.data, key, cval)
Append child nodes into L{Content.data}
        @param content: The current content being unmarshalled.
        @type content: L{Content}