def ancestor?(fei)

      fei = fei.to_h if fei.respond_to?(:to_h)

      return false unless h.parent_id
      return true if h.parent_id == fei

      parent.ancestor?(fei)
    end
def ancestor?(fei)

      fei = fei.to_h if fei.respond_to?(:to_h)

      return false unless h.parent_id
      return true if h.parent_id == fei

      parent.ancestor?(fei)
    end
Returns true if the given fei points to an expression in the parent
 chain of this expression.