duplicate keys in a stream are ignored

[anuragde]

I have two streams for inner join:

Stream1 : Seq(("key1", 1), ("key3", 1), ("key2", 2))
Stream2: Seq(("key1", 3), ("key2", 1), ("key2", 2))

Expected Stream after inner-join (with addition as result) between Stream1 and Stream2: Seq(("key1", 4), ("key2", 3), ("key2", 4)) but I get the actual output as Seq(("key1", 4), ("key2", 3))