if buffer:
                self.write(" ", *buffer)
            self.write(": ")
            self.set_precedence(_Precedence.TEST, node.body)
            self.traverse(node.body)
    def visit_alias(self, node):
        self.write(node.name)
        if node.asname:
            self.write(" as " + node.asname)
    def visit_withitem(self, node):
        self.traverse(node.context_expr)
        if node.optional_vars:
            self.write(" as ")
            self.traverse(node.optional_vars)
    def visit_match_case(self, node):
        self.fill("case ")
        self.traverse(node.pattern)
        if node.guard:
            self.write(" if ")
            self.traverse(node.guard)
        with self.block():
            self.traverse(node.body)
    def visit_MatchValue(self, node):
        self.traverse(node.value)
    def visit_MatchSingleton(self, node):
        self._write_constant(node.value)
    def visit_MatchSequence(self, node):
        with self.delimit("[", "]"):
            self.interleave(
                lambda: self.write(", "), self.traverse, node.patterns
            )
    def visit_MatchStar(self, node):
        name = node.name
        if name is None:
            name = "_"
        self.write(f"*{name}")
    def visit_MatchMapping(self, node):
        def write_key_pattern_pair(pair):
            k, p = pair
            self.traverse(k)
            self.write(": ")
            self.traverse(p)
        with self.delimit("{", "}"):
            keys = node.keys
            self.interleave(
                lambda: self.write(", "),
                write_key_pattern_pair,
                zip(keys, node.patterns, strict=True),