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