code: public static <CL extends ClassUml>
        Point2D[] evalTwoLinesForAngle(SettingsGraphicUml gp, ClassRelationFull<CL> relClrel) {
      Point2D pointEnd2 = null;
      if(relClrel.getRelationship().getSharedJoint() == null) {//from this to across relClrel
        RectangleRelationship<ClassFull<CL>, CL> nextRelationClass = relClrel.getRelationship().getShapeRelationshipStart() == relClrel.getClassRelationship() ?
            relClrel.getRelationship().getShapeRelationshipEnd() : 
              relClrel.getRelationship().getShapeRelationshipStart();
        pointEnd2 = nextRelationClass.getPointJoint();      
      }
      else {//from this to interJoint
        pointEnd2 = new Point2D(relClrel.getRelationship().getSharedJoint().getX(), 
            relClrel.getRelationship().getSharedJoint().getY());
      }
      Point2D pointEnd1 = new Point2D(relClrel.getClassRelationship().getPointJoint().getX(), relClrel.getClassRelationship().getPointJoint().getY());
      if(relClrel.getClassRelationship().getSideJoint() == EJointSide.BOTTOM || relClrel.getClassRelationship().getSideJoint() == EJointSide.TOP) {
        pointEnd1.setX(pointEnd2.getX());
      }
      else {
        pointEnd1.setY(pointEnd2.getY());
      }
      return new Point2D[]{relClrel.getClassRelationship().getPointJoint(), pointEnd1, pointEnd2};
    }
docs: <p>Evaluate 3 points of 2 lines</p>
  @param gp
  @param relClrel
  @return [pointShared, pointEndLine1, pointEndLine2]