diff static method
Get diff from two modes
Implementation
static int diff(dynamic a1, dynamic a2) {
var a1d = AccessMode.decode(a1) ?? 0;
var a2d = AccessMode.decode(a2) ?? 0;
if (a1d == INVALID || a2d == INVALID) {
return INVALID;
}
return a1d & ~a2d;
}