$\int_{-\infty}^\infty \frac{x^2}{x^4-2x^2\cos 2\theta+1}\,dx$ by residues

Compute \(\int _ { - \infty } ^ { \infty } \frac { x ^ { 2 } } { x ^ { 4 } - 2 x ^ { 2 } \cos 2 \theta + 1 } \mathrm { d } x ;\)