code: public PositionAlignmentOptions setVerticalAlignment(PositionRelation verticalAlignment, int offsetTop)
  	{
  		switch (verticalAlignment)
  		{
  			case TOP:
  			case CENTER:
  			case BOTTOM:
  				break;
  			default:
  				throw new IllegalArgumentException("Illegal value for the vertical alignment property");
  		}
  
  		this.verticalAlignment = verticalAlignment;
  		this.offsetTop = offsetTop;
  		return this;
  	}
docs: Set the verticalAlignment property with an offset. One of TOP, CENTER, BOTTOM.
  
  @param verticalAlignment
  @param offsetTop
  @return the instance