SNAPSHOTCOPYTOMARK function behaves like
SNAPSHOTTOMARK but does not consume the elements of the stack, instead it produces WarpScript code which will regenerate the stack as it was before the call and pushes this code on top of the stack.
Note that some types of objects created by third party functions may not be serializable,
SNAPSHOTCOPYTOMARK will emit a STRING of the form
UNSUPPORTED: class xxx when such a type is encountered.