text: // Arguments: Doubles, Doubles, Doubles, Doubles
  #include <stan/math/prim/scal.hpp>
  
  using stan::math::var;
  using std::numeric_limits;
  using std::vector;
  
  class AgradCdfLogStudentT : public AgradCdfLogTest {
   public:
    void valid_values(vector<vector<double> >& parameters,
                      vector<double>& cdf_log) {
      vector<double> param(4);
  
      param[0] = 5.0;  // y
      param[1] = 1.5;  // nu (Degrees of Freedom)
      param[2] = 3.3;  // mu (Location)
      param[3] = 1.0;  // sigma (Scale)
      parameters.push_back(param);
      cdf_log.push_back(std::log(0.8646688779244795508561));  // expected CDF_log
  
      param[0] = 2.5;  // y
      param[1] = 3.5;  // nu (Degrees of Freedom)
      param[2] = 3.3;  // mu (Location)
      param[3] = 1.0;  // sigma (Scale)
      parameters.push_back(param);
      cdf_log.push_back(std::log(0.2372327883473262233327));  // expected CDF_log
    }
  
    void invalid_values(vector<size_t>& index, vector<double>& value) {
      // nu
      index.push_back(1U);
      value.push_back(-1.0);
  
      index.push_back(1U);
      value.push_back(0.0);
  
      index.push_back(1U);
      value.push_back(numeric_limits<double>::infinity());
  
      // mu
      index.push_back(2U);
      value.push_back(-numeric_limits<double>::infinity());
  
      index.push_back(2U);
      value.push_back(numeric_limits<double>::infinity());
  
      // sigma
      index.push_back(3U);
      value.push_back(-1.0);
  
      index.push_back(3U);
      value.push_back(0.0);
  
      index.push_back(3U);
      value.push_back(numeric_limits<double>::infinity());
    }
  
    bool has_lower_bound() { return false; }
  
    bool has_upper_bound() { return false; }
  
    template <typename T_y, typename T_dof, typename T_loc, typename T_scale,
              typename T4, typename T5>
    typename stan::return_type<T_y, T_dof, T_loc, T_scale>::type cdf_log(
        const T_y& y, const T_dof& nu, const T_loc& mu, const T_scale& sigma,
        const T4&, const T5&) {
      return stan::math::student_t_cdf_log(y, nu, mu, sigma);
    }
  
    template <typename T_y, typename T_dof, typename T_loc, typename T_scale,
              typename T4, typename T5>
    typename stan::return_type<T_y, T_dof, T_loc, T_scale>::type cdf_log_function(
        const T_y& y, const T_dof& nu, const T_loc& mu, const T_scale& sigma,
        const T4&, const T5&) {
      return stan::math::student_t_cdf_log(y, nu, mu, sigma);
    }
  };
  