* Adds an internal constrained boolean variable to the Constrainer. Used in
* expressions that create internal variables for their own needs. <br>
* <b>Note:</b>Constrainer's users should not use this method.
*/
public IntBoolVar addIntBoolVarInternal(String name) {
IntBoolVar var = new IntBoolVarImpl(this, name);
return addIntBoolVarInternal(var);
}