public override void OnGUI(Rect position, SerializedProperty property, GUIContent label)
{
HexPoint coordinates = new HexPoint(
property.FindPropertyRelative("x").intValue,
property.FindPropertyRelative("z").intValue
);
label = new GUIContent("Coordinates");
position = EditorGUI.PrefixLabel(position, label);
GUI.Label(position, coordinates.ToString());
}