(1) Draw the locus of points $(x,y)$ which satisfy the following equation.
$bx^{3}+y^{3}+x^{2}y+bxy^{2}-4abxy-2ab^{2}x^{2}-2ay^{2}+b\left( a^{2}b^{2}+a^{2}-1\right)x+\left( a^{2}b^{2}+a^{2}-1\right) y=0 $
(2) When the locus can be drawn with a single stroke, show the relation between $a$ and $b$.
Thank you very much :)