private void updateButtonStates() {
        updateAddFromInputEnabledState();
        updateClearInputVisibleState();
        updateAddFromAllTagsEnabledState();
        updateRemoveEnabledState();
    }
@return Trimmed and lower-cased tag.
stroom-core-client/src/main/java/stroom/explorer/client/view/ExplorerNodeEditTagsViewImpl.java