message: include once
diff: * @file
  * @copyright defined in eos/LICENSE.txt
  */
  +#pragma once
  +
  #include <eos/chain/key_value_object.hpp>
  namespace eos { namespace chain {
  @@ -339,3 +341,4 @@ struct upper_bound_tuple<key64x64x64_value_object, by_scope_tertiary> {
  };
  } } // eos::chain
  +
  