code: def integrate(self,t,pot=None,method='test-particle',
                    **kwargs):
          
          if method.lower() == 'test-particle':
              return self._integrate_test_particle(t,pot)
          elif method.lower() == 'direct-python':
              return self._integrate_direct_python(t,pot,**kwargs)
docs: NAME:
             integrate
          PURPOSE:
             integrate the snapshot in time
          INPUT:
             t - numpy.array of times to save the snapshots at (must start at 0)
             pot= potential object or list of such objects (default=None)
             method= method to use ('test-particle' or 'direct-python' for now)
          OUTPUT:
             list of snapshots at times t
          HISTORY:
             2011-02-02 - Written - Bovy (NYU)