pass
    # Overridable -- handle data
    def handle_data(self, data):
        pass
    # Overridable -- handle comment
    def handle_comment(self, data):
        pass
    # Overridable -- handle declaration
    def handle_decl(self, decl):
        pass
    # Overridable -- handle processing instruction
    def handle_pi(self, data):
        pass
    def unknown_decl(self, data):
        pass