code: def integrator(self):
          
          i = self._integrator
          for name, _i in INTEGRATORS.items():
              if i==_i:
                  return name
          return i
docs: Get or set the intergrator module.
  
          Available integrators are:
  
          - ``'ias15'`` (default)
          - ``'whfast'``
          - ``'sei'``
          - ``'leapfrog'``
          - ``'janus'``
          - ``'mercurius'``
          - ``'bs'``
          - ``'none'``
          
          Check the online documentation for a full description of each of the integrators.