code: public Object getValue(String propertyPath, Object defaultValue) {
  		Object o = null;
  		try {
  			o = getValue(propertyPath);
  		} catch (PropertyException e) {
  			return defaultValue;
  		}
  		return o;
  	}
docs: Get the value from the property path. If the property path does not
  exist, the default value is returned.
  
  @param propertyPath
  Example: foo.bar.key
  @param defaultValue
  is returned when the propertyPath does not exist
  @return the value from the propertyPath.