#347 Add 'contains' method to PropertyType

src/main/java/fr/xephi/authme/settings/domain/EnumPropertyType.java

@@ -33,6 +33,12 @@ class EnumPropertyType<E extends Enum<E>> extends PropertyType<E> {
         return asList("'" + value + "'");
     }
 
+    @Override
+    public boolean contains(Property<E> property, YamlConfiguration configuration) {
+        return super.contains(property, configuration)
+            && mapToEnum(configuration.getString(property.getPath())) != null;
+    }
+
     private E mapToEnum(String value) {
         for (E entry : clazz.getEnumConstants()) {
             if (entry.name().equalsIgnoreCase(value)) {

src/main/java/fr/xephi/authme/settings/domain/PropertyType.java

@@ -49,6 +49,10 @@ public abstract class PropertyType<T> {
      */
     protected abstract List<String> asYaml(T value);
 
+    protected boolean contains(Property<T> property, YamlConfiguration configuration) {
+        return configuration.contains(property.getPath());
+    }
+
 
     /**
      * Boolean property.