'oneof' fields are not injected on request about rejoiner HOT 2 CLOSED

I created PR #67 to address this issue.
A possible corner case is if a user sets multiple unique legal fields of a oneof, i.e, given

 oneof some_val{
string val_a =1;
int64 val_b=2;
}

and

builder.setValA("foo").setValB(123)

, the last oneof value setter called on the builder is the one that survives, according to the protobuf language specification. So ordering of the input map is consequential and should be preserved. The other case where a user sets the same oneof filed multiple times, i.e

builder.setValA("foo").setValA("bar")

already throws a duplicate key exception by the existing code.

from rejoiner.

This works as expected - my error must've been syntax related.

from rejoiner.