ProblemChange (OptaPlanner Javadoc 8.20.0.Final API)

Type Parameters:

Solution_ - the solution type, the class with the PlanningSolution annotation

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
```
@FunctionalInterface
public interface ProblemChange<Solution_>
```
A ProblemChange represents a change in 1 or more planning entities or problem facts of a PlanningSolution. Problem facts used by a Solver must not be changed while it is solving, but by scheduling this command to the Solver, you can change them when the time is right.
Note that the Solver clones a PlanningSolution at will. Any change must be done on the problem facts and planning entities referenced by the PlanningSolution of the ProblemChangeDirector.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`doChange(Solution_ workingSolution, ProblemChangeDirector problemChangeDirector)`	Do the change on the `PlanningSolution`.

- Method Detail
  - doChange
```
void doChange(Solution_ workingSolution,
              ProblemChangeDirector problemChangeDirector)
```
    Do the change on the PlanningSolution. Every modification to the PlanningSolution must be done via the ProblemChangeDirector, otherwise the Score calculation will be corrupted.
    
    Parameters:
    
    workingSolution - never null; the working solution which contains the problem facts (and planning entities) to change
    
    problemChangeDirector - never null; ProblemChangeDirector to perform the change through