code: public int dataToFields(Rec record) throws DBException
      {
          if (((BaseBuffer)this.getHandle(DBConstants.DATA_SOURCE_HANDLE)) == null)
              throw new DBException(DBConstants.INVALID_RECORD);
          ((BaseBuffer)this.getHandle(DBConstants.DATA_SOURCE_HANDLE)).resetPosition();
          return super.dataToFields(record);
      }
docs: Move the data source buffer to all the fields.<p>
  Make sure you do the following steps:
  1) Move the data fields to the correct record data fields.
  2) Save the data source or set to null, so I can cache the source if necessary.
  3) Save the objectID if it is not an Integer type, so I can serialize the source of this object.
  @return The error code.
  @exception DBException File exception.