When using multiple Read/Write/State transformers in the same monad stack, it
becomes necessary to lift the operations in order to affect a specific
transformer. Using heterogeneous lists (and all kinds of GHC extensions magic),
this package provides transformers that remove that necessity:
MultiReaderT/MultiWriterT/MultiStateT/MultiRWST can contain a heterogeneous
list of values.
See the <https://github.com/lspitzner/multistate README> for a longer