Bug 17256 Exception due to bug 17208
bundles/org.eclipse.core.databinding/src/org/eclipse/core/databinding/validation/String2DateValidator.java
IValidator {
	public IStatus validate(Object value) {
		return parse((String) value) != null ? Status.OK_STATUS
				: ValidationStatus.error(getHint());
	}
	private String getHint() {
		Date sampleDate = new Date();
		StringBuffer samples = new StringBuffer();
		for (int formatterIdx = 1; formatterIdx < numFormatters() - 2; formatterIdx++) {
			samples.append('\'');
			samples.append(format(sampleDate, formatterIdx));
			samples.append("', "); 
		}
		samples.append('\'');
		samples.append(format(sampleDate, 0));
		samples.append('\'');
		return BindingMessages.getString("Examples") + ": " + samples + ",..."; 
	}
}