code: public boolean isJDBCDriver(String jdbcDriverName) throws Exception {
          Address addr = Address.root().add(SUBSYSTEM, SUBSYSTEM_DATASOURCES);
          String haystack = JDBC_DRIVER;
          return null != findNodeInList(addr, haystack, jdbcDriverName);
      }
docs: Checks to see if there is already a JDBC driver with the given name.
  
  @param jdbcDriverName the name to check
  @return true if there is a JDBC driver with the given name already in existence
  @throws Exception any error