code: public static final Box getBox(View v)
      {
          if (v instanceof CSSBoxView) return getBox((CSSBoxView) v);
  
          AttributeSet attr = v.getAttributes();
          if (attr == null)
          {
              throw new NullPointerException("AttributeSet of " + v.getClass().getName() + "@"
                                  + Integer.toHexString(v.hashCode()) + " is set to NULL.");
          }
          Object obj = attr.getAttribute(Constants.ATTRIBUTE_BOX_REFERENCE);
          if (obj != null && obj instanceof Box)
          {
              return (Box) obj;
          }
          else
          {
              throw new IllegalArgumentException("Box reference in attributes is not an instance of a Box.");
          }
  
      }
docs: Gets the box reference from properties.
  
  @param v
  just a view.
  @return the box set in properties, if there is one.