code: protected Variable[] createVariablesSub(int num, String component) {
  		Variable[] ret = createVariablesSub(num);
  		if (component != null) {
  			logger.finest("Set component of " + Arrays.toString(ret) + " to " + component);
  			this.setComponent(component, ret);
  		}
  		return ret;
  	}
docs: This method must be implemented by the developer of the specific {@link ConstraintSolver}
  class.  It should implement all operations necessary to create a batch of variable for the specific
  type of {@link ConstraintSolver}.
  @param component The component label to associate to the new {@link Variable}s.
  @param num The number of {@link Variable}s to create.
  @return A batch of new {@link Variable} for this {@link ConstraintSolver}.