Two circles in the first quadrant of radii \( r_{1} \) and \( r_{2} \) touch the coordinate axes. Each of them cuts off an intercept of \( 2 \) units with the line \( x+y=2 \). Then \( r_{1}^{2}+r_{2}^{2}-r_{1}r_{2} \) is equal to _____.
