Bug 80429 [Preferences] [Dialogs] FieldEditors should relax requirements to support DialogPages
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/FieldEditor.java
String text = getLabelText();
            if (text != null)
                label.setText(text);
            label.addDisposeListener(new DisposeListener() {
                public void widgetDisposed(DisposeEvent event) {
                    label = null;
                }
            });
        } else {
            checkParent(label, parent);
        }
        return label;
    }
    /**
     * Returns this field editor's label text.
     *
     * @return the label text
     */
    public String getLabelText() {
        return labelText;
    }
    /**
     * Returns the number of basic controls this field editor consists of.
     *
     * @return the number of controls
     */
    public abstract int getNumberOfControls();
    /**
     * Returns the name of the preference this field editor operates on.
     *