AnchorShadowVariable (OptaPlanner Javadoc 8.15.0.Final API)

```
@Target({METHOD,FIELD})
@Retention(RUNTIME)
public @interface AnchorShadowVariable
```
Specifies that a bean property (or a field) is the anchor of a chained PlanningVariable, which implies it's a shadow variable.
It is specified on a getter of a java bean property (or a field) of a PlanningEntity class.

- Required Element Summary
  
  Required Elements
  Modifier and Type Required Element Description
  
  String sourceVariableName
  The source planning variable is a chained planning variable that leads to the anchor.

- Element Detail
  - sourceVariableName
```
String sourceVariableName
```
    The source planning variable is a chained planning variable that leads to the anchor.
    Both the genuine variable and the shadow variable should be consistent: if A chains to B, then A must have the same anchor as B (unless B is the anchor).
    When the Solver changes a genuine variable, it adjusts the shadow variable accordingly. In practice, the Solver ignores shadow variables (except for consistency housekeeping).
    
    Returns:
    
    the variable property name on this entity class that leads to the anchor