code: protected JdbcQueueFactory<T, ID, DATA> setDefaultJdbcHelper(IJdbcHelper jdbcHelper,
              boolean setMyOwnJdbcHelper) {
          if (myOwnJdbcHelper && this.defaultJdbcHelper != null
                  && this.defaultJdbcHelper instanceof AbstractJdbcHelper) {
              ((AbstractJdbcHelper) this.defaultJdbcHelper).destroy();
          }
          this.defaultJdbcHelper = jdbcHelper;
          this.myOwnJdbcHelper = setMyOwnJdbcHelper;
          return this;
      }
docs: Setter for {@link #defaultJdbcHelper}.
  
  @param jdbcHelper
  @param setMyOwnJdbcHelper
  @return
  @since 0.7.1