text: #ifndef BESSEL_LAYER_SIM
  #define BESSEL_LAYER_SIM
  
  #include <RcppArmadillo.h>
  #include <vector>
  #include <algorithm>
  #include <random>
  
  using namespace Rcpp;
  
  Rcpp::List bessel_layer_simulation(const double &x,
                                     const double &y,
                                     const double &s,
                                     const double &t,
                                     const double &mult);
  
  Rcpp::List multi_bessel_layer_simulation(const int &dim,
                                           const arma::vec &x,
                                           const arma::vec &y,
                                           const double &s,
                                           const double &t,
                                           const double &mult);
    
  #endif