code: public boolean supportsTransactionIsolationLevel(
              int level) throws SQLException {
  
          return level == Connection.TRANSACTION_READ_UNCOMMITTED
                 || level == Connection.TRANSACTION_READ_COMMITTED
                 || level == Connection.TRANSACTION_REPEATABLE_READ
                 || level == Connection.TRANSACTION_SERIALIZABLE;
      }
docs: Retrieves whether this database supports the given transaction isolation level.
  
  <!-- start release-specific documentation -->
  <div class="ReleaseSpecificDocumentation">
  <h3>HSQLDB-Specific Information</h3>
  HSQLDB supports all levels.
  </div>
  <!-- end release-specific documentation -->
  
  
  @param level one of the transaction isolation levels defined in
  <code>java.sql.Connection</code>
  @return <code>true</code> if so; <code>false</code> otherwise
  @exception SQLException if a database access error occurs
  @see JDBCConnection