fun followedBy(tail: Message): MessageChain
将 this 和 tail 连接.
连接后可以保证 ConstrainSingle 的元素单独存在.
例:
val a = PlainText("Hello ")
val b = PlainText("world!")
val c: MessageChain = a + b
println(c) // "Hello world!"
val d = PlainText("world!")
val e = c + d; // PlainText + CombinedMessage
println(c) // "Hello world!"
See Also