code: def _integrate_fixed_trajectory(self, h, T, step, relax):
          
          # initialize the solution using initial condition
          solution = np.hstack((self.t, self.y))
  
          while self.successful():
  
              self.integrate(self.t + h, step, relax)
              current_step = np.hstack((self.t, self.y))
              solution = np.vstack((solution, current_step))
  
              if (h > 0) and (self.t >= T):
                  break
              elif (h < 0) and (self.t <= T):
                  break
              else:
                  continue
  
          return solution
docs: Generates a solution trajectory of fixed length.