code: public Matrix4x3d reflect(Vector3dc normal, Vector3dc point) {
          return reflect(normal.x(), normal.y(), normal.z(), point.x(), point.y(), point.z());
      }
docs: Apply a mirror/reflection transformation to this matrix that reflects about the given plane
  specified via the plane normal and a point on the plane.
  <p>
  If <code>M</code> is <code>this</code> matrix and <code>R</code> the reflection matrix,
  then the new matrix will be <code>M * R</code>. So when transforming a
  vector <code>v</code> with the new matrix by using <code>M * R * v</code>, the
  reflection will be applied first!
  
  @param normal
  the plane normal
  @param point
  a point on the plane
  @return this