refactor: change problem constructors to XProblem(sys, op[, tspan])
#4342
| Job | Run time |
|---|---|
| 1m 1s | |
| 35s | |
| 1m 36s |
XProblem(sys, op[, tspan])
#4342
| Job | Run time |
|---|---|
| 1m 1s | |
| 35s | |
| 1m 36s |