Constrained optimization problem by particle swarm algorithm

Hello, I have been working on programming the algorithm of particle swarm optimization and have successfully employed it to various unconstrained optimization test functions. but now I want to test the algorithm with the constrained optimization test functions. One example is the rosenbrock,s test function with constraints. I have successfully optimized this function with no constraints. Now, is anybody willing to help me. Thank you :)

Rosenbrock,s function

min (1-x)^2+100((y-x^2)^2) sub to x^2 +y^2 <2