pure interface of class Graph1

public abstract class Graph1
  extends Drawable
{
    public int left;
    public int right;
    public int bot;
    public int top;
    public Constraints C;
    public Interface source;
    public Interface target;
    public int controlIn;
    public int controlOut;
    public Graph1(Constraints C,
                  Interface source,
                  Interface target,
                  int controlIn,
                  int controlOut);
    public Graph1 pad();
}