setWarningMessage

The user can be informed about anything strange happened during the execution of the node with this method. This will not cancel execution but set a warning icon with the provided message as the tooltip.

Example #1:

if (m_includedColumns.getIncludeList() == null 
    || m_includedColumns.getIncludeList().size() <= 0) {
    setWarningMessage(
        "No columns to transfrom selected. Will have no effect!");
}