docs: def get_ref_indices(self):
          """
          :return: list of all indices in object reference.
          """
  
          ixn_obj = self
          ref_indices = []
          while ixn_obj != ixn_obj.root:
              ref_indices.append(ixn_obj.ref.split(':')[-1])
              ixn_obj = ixn_obj.parent
          return ref_indices[::-1]