$L 文本值
("a= b $L c $L d", "-","+") -> a = b-c+d
("s = $L<$L", "a","b") -> s = a<b
$S 字符串
（"$S","hello"） -> "hello"
$T 对象
("$T.out.println()",System.class) -> System.out.println()
$N
MethodSpec haha = MethodSpec .methodBuilder("haha").build()
("$N()",haha) -> haha()
("this.$N = $N","a","a") -> this.a = a
