public abstract class Base {
  /** Attributes */
  public static int dummy;
  private int x = 0;
  /**
   * Operation
   *
   * @param a
   * @return int
   */
  abstract public int foo ( int a );
  /**
   * Operation
   *
   * @param x
   * @param y
   * @return int
   */
  abstract protected int bar ( int x, int y );
}

import Base;
import PureAbstract;

public class Derived extends Base implements PureAbstract {
  /**
   * Operation
   *
   * @param a
   * @return int
   */
  public int foo ( int a ){
  }
  /**
   * Operation
   *
   * @return int
   */
  public static int newfoo (  ){
  }
  /**
   * Operation
   *
   * @return int
   */
  public int otherfoo (  ){
  }
  /**
   * Operation
   *
   * @param x
   * @param y
   * @return int
   */
  protected int bar ( int x, int y ){
  }
}

public interface PureAbstract {
  /**
   * Operation
   *
   * @return int
   */
  abstract public int otherfoo (  );
}