_entityIndexListViewer.addSelectionChangedListener(_buttonUpdateListener);
Combo attributesCombo = new Combo(this, SWT.BORDER | SWT.FLAT | SWT.READ_ONLY);
_attributesComboViewer = new ComboViewer(attributesCombo);
_attributesComboViewer.setLabelProvider(new EOAttributesLabelProvider(new String[] { AbstractEOArgument.NAME }));
_attributesComboViewer.setContentProvider(new EOAttributesContentProvider());
GridData attributesComboLayoutData = new GridData(GridData.FILL_HORIZONTAL);
attributesCombo.setLayoutData(attributesComboLayoutData);
_addRemoveButtonGroup = new AddRemoveButtonGroup(this, new AddAttributeHandler(), new RemoveAttributesHandler());
}