package cal;

public abstract class TrigoOperator extends Operator{

	public TrigoOperator(String sign) {
		super(sign);
	}
}

package cal;

/**
 * 
 * @author huiming
 *
 */
public abstract class TrigoOperator extends Operator{

	public TrigoOperator(String sign) {
		super(sign);
	}
}

Create a new branch for Java Doc