code: public Matrix4f scale(float x, float y, float z) {
          return scale(x, y, z, thisOrNew());
      }
docs: Apply scaling to this matrix by scaling the base axes by the given sx,
  sy and sz factors.
  <p>
  If <code>M</code> is <code>this</code> matrix and <code>S</code> the scaling matrix,
  then the new matrix will be <code>M * S</code>. So when transforming a
  vector <code>v</code> with the new matrix by using <code>M * S * v</code>, the
  scaling will be applied first!
  
  @param x
  the factor of the x component
  @param y
  the factor of the y component
  @param z
  the factor of the z component
  @return a matrix holding the result