"Given a function with a single parameter of tuple type 
 `[P1, P2, ..., Pn]`, return a function with multiple 
 parameters of type `P1`, `P2`, ..., `Pn`.
 
 That is, if `fun` has type `W([X,Y,Z])` then `flatten(fun)` 
 has type `W(X,Y,Z)`."
see(`function unflatten`)
shared native Callable<Return,Args> flatten<Return,Args>(Return tupleFunction(Args tuple))
        given Args satisfies Anything[];