Bug 294303 [Markers] 'Queuing Viewer Updates' in Problems view
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/views/markers/ExtendedMarkersView.java
* @return Clipboard
	 */
	Clipboard getClipboard() {
		if (clipboard == null)
			clipboard = new Clipboard(viewer.getControl().getDisplay());
		return clipboard;
	}
	/**
	 * Return the content provider for the receiver.
	 * 
	 * @return ITreeContentProvider
	 * 
	 */
	private IContentProvider getContentProvider() {
		return new MarkerViewerContentProvider();
	}
	/**
	 * Get the id of the marker field in treeColumn.
	 * 
	 * @param treeColumn
	 * @return String
	 */
	private String getFieldId(TreeColumn treeColumn) {
		return ((MarkerField) treeColumn.getData(MARKER_FIELD))
				.getConfigurationElement().getAttribute(
						MarkerSupportInternalUtilities.ATTRIBUTE_ID);
	}
	/**
	 * Return the ids of the generators specified for the receiver.
	 *