code: public void setScale(Tuple2D<?> tuple) {
  		assert tuple != null : AssertMessages.notNullParameter();
  		setScale(tuple.getX(), tuple.getY());
  	}
docs: Set the scale.
  
  <p>This function changes only the elements of
  the matrix related to the scaling (m00,
  m11). The shearing and the translation are not changed.
  The rotation is lost.
  
  <p>After a call to this function, the matrix will
  contains (? means any value):
  <pre>
  [   t.x  ?    ?   ]
  [   ?    t.y  ?   ]
  [   ?    ?    ?   ]
  </pre>
  
  @param tuple the scaling factors.
  @see #makeScaleMatrix(double, double)