Bug 169637 [DataBinding] Multiple validation statuses per binding
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/ValueBinding.java
super(targetObservableValue, modelObservableValue);
		this.target = targetObservableValue;
		this.model = modelObservableValue;
		this.targetToModel = targetToModel;
		this.modelToTarget = modelToTarget;
		if ((targetToModel.getUpdatePolicy() & (UpdateValueStrategy.POLICY_CONVERT | UpdateValueStrategy.POLICY_UPDATE)) != 0) {
			target.addValueChangeListener(targetChangeListener);
		} else {
			targetChangeListener = null;
		}
		if ((modelToTarget.getUpdatePolicy() & (UpdateValueStrategy.POLICY_CONVERT | UpdateValueStrategy.POLICY_UPDATE)) != 0) {
			model.addValueChangeListener(modelChangeListener);
		} else {
			modelChangeListener = null;
		}
	}
	protected void preInit() {
		validationStatusObservable = new WritableValue(context
				.getValidationRealm(), Status.OK_STATUS, IStatus.class);
	}
	protected void postInit() {
		if (modelToTarget.getUpdatePolicy() == UpdateValueStrategy.POLICY_UPDATE) {
			updateModelToTarget();
		}
		if (targetToModel.getUpdatePolicy() != UpdateValueStrategy.POLICY_NEVER) {
			validateTargetToModel();
		}
	}
	public IObservableValue getValidationStatus() {
		return validationStatusObservable;