def set_properties(hash)
      hash.each do |key, value|
        add_or_remove_ostruct_member(key, value)
      end
      rest_reset_properties
    end
def set_properties(hash)
      hash.each do |key, value|
        add_or_remove_ostruct_member(key, value)
      end
      rest_reset_properties
    end
Set many properties at once and only issue one http
 request and update the node/relationship instance on the fly.

 To remove a property, set its value to nil.