code: public void scale(Tuple2D<?> tuple) {
  		assert tuple != null : AssertMessages.notNullParameter();
  		scale(tuple.getX(), tuple.getY());
  	}
docs: Concatenates this transform with a scaling transformation.
  
  <p>This function is equivalent to:
  <pre>
  this = this *  [   t.x   0     0   ]
  [   0     t.y   0   ]
  [   0     0     1   ]
  </pre>
  
  @param tuple the scaling factors.