code: def _isDissipative(obj):
      
      from .Potential import flatten
      obj= flatten(obj)
      isList= isinstance(obj,list)
      if isList:
          isCons= [not isinstance(p,DissipativeForce) for p in obj]
          nonCons= not numpy.prod(numpy.array(isCons))
      else:
          nonCons= isinstance(obj,DissipativeForce)
      return nonCons
docs: NAME:
  
         _isDissipative
  
      PURPOSE:
  
         Determine whether this combination of potentials and forces is Dissipative
  
      INPUT:
  
         obj - Potential/DissipativeForce instance or list of such instances
  
      OUTPUT:
  
         True or False depending on whether the object is dissipative
  
      HISTORY:
  
         2018-03-16 - Written - Bovy (UofT)