logTreeViewer = new CheckboxTreeViewer(group, SWT.BORDER);
GridData data = new GridData(GridData.FILL_BOTH);
data = new GridData(GridData.FILL_BOTH);
logTreeViewer.getControl().setLayoutData(data);
logTreeViewer.setContentProvider(new VdmLogTreeContentProvider());
logTreeViewer.setLabelProvider(new VdmLogTreeLabelProvider());
logTreeViewer.setCheckStateProvider(this);
}