init Subroutine

  subroutine init(this, d_tol, r_tol)
    class(tester_t), intent(out) :: this
    double precision, intent(in), optional :: d_tol
    real, intent(in), optional :: r_tol

    this% n_errors = 0
    this% n_tests = 0

    if (present(d_tol)) then
       this% d_tol = d_tol
    else
       this% d_tol = 2.d0*epsilon(1.d0)
    end if

    if (present(r_tol)) then
       this% r_tol = r_tol
    else
       this% r_tol = 2.*epsilon(1.)
    end if

  end subroutine init