Write a Monte Carlo code for a fluid of \(N\) hard spheres in a two-dimensional \(L \times L\) square box with periodic boundary conditions in each direction. Calculate the pair correlation function and determine the scaled pressure using equation (10.7.12), namely \(P / n k T=1+2 \eta g\left(D^{+}\right)\). Compare this pressure to the approximate form \(P / n k T=(1+\eta / 8) /(1-\eta)^{2}\).