well the param in `SparseRandomProjection` is not consistent  with the param name in `OneHoteEncoder`. All I am saying is that rather than reusing the suboptimal param name  in `OneHoteEncoder` for `RandomTreesEmbedding` I woud rather reuse the name from `SparseRandomProjection` which I find more descriptive.

Changing existing name is annoying as we need to deal with backward compat.