Why does Stream.Builder have both add and accept methods?

Question

I was using a Stream.Builder and I stumbled upon the fact that this interface has both the methods accept(T t) and add(T t). The only difference is that the former returns void and the latter returns a Stream.Builder.

The documentation even mentions these methods to have the same default implementation:

The default implementation behaves as if:

accept(t) return this; 

^{Note that they forgot a semicolon, but that's another story.}

My question is: why do they have two methods to add something to the stream builder? I think this clutters the API, and I thought they wanted to avoid that.

Is there any compelling reason to do so?

Answer 1

My guess:

Stream.Builder extends Consumer<T> so it must implement the accept(T) method.

But accept(T) returns void, so I think they added add(T) for convenience: methods in a builder pattern implementation often return this to be able to chain the building and finally call build().