code: def find(cls, id='', slug=None):
          
  
          if not id and not slug:
              return None
          try:
              return cls.where(id=id, slug=slug).next()
          except StopIteration:
              raise PanoptesAPIException(
                  "Could not find collection with slug='{}'".format(slug)
              )
docs: Similar to :py:meth:`.PanoptesObject.find`, but allows lookup by slug
          as well as ID.
  
          Examples::
  
              collection_1234 = Collection.find(1234)
              my_collection = Collection.find(slug="example/my-collection")