[h2o-3 ]Is there an existing solution to swaping two vectors in h2o-3?

Question

Lets say theres a Frame fr consisting of 3 vectors with column names "a" "b" "c". I have an MRTask giving me a new vector. Vec new_vec_a = FooReturningNewVec(fr.vec("a")). Now I want to swap fr.vec("a") with new_vec_a.

Can I use an already existing method, if not how would you suggest on creating this method.