A pretzel is to be dipped in chocolate. The pretzel is in the shape of a quarter circle,
consisting of a straight segment from the origin to the point (2,0), a circular arc from there
to (0,2), followed by a straight segment back to the origin; all distances are in centimeters.
The (linear) density of chocolate on the pretzel is given by \(\lambda = 3(x^ 2 + y^2 )\) in grams per
centimeter. Find the total amount of chocolate on the pretzel.