Returns true if and only if the UUID is equal to {00000000-0000-0000-0000-000000000000}
UUID id; assert(id.empty); id = UUID("00000000-0000-0000-0000-000000000001"); assert(!id.empty);
See Implementation
Returns true if and only if the UUID is equal to {00000000-0000-0000-0000-000000000000}