code: @WithBridgeMethods(value = SQLInsertClause.class, castRequired = true)
      public C addFlag(Position position, Expression<?> flag) {
          metadata.addFlag(new QueryFlag(position, flag));
          return (C) this;
      }
docs: Add the given Expression at the given position as a query flag
  
  @param position position
  @param flag query flag
  @return the current object