code: @SuppressWarnings({"unchecked", "rawtypes"})
      public List<E> getValueAsList() {
  
          final Object fieldValue = getValue();
          final Class<?> fieldType = getType();
  
          if(Collection.class.isAssignableFrom(fieldType)) {
              final Collection<Object> value = (fieldValue == null ? new ArrayList<Object>() : (Collection<Object>) fieldValue);
              final List<Object> list = Utils.convertCollectionToList(value);
              return (List)list;
  
          } else if(fieldType.isArray()) {
              Class<?> componentType = fieldType.getComponentType();
              final List<Object> list = Utils.asList(fieldValue, componentType);
              return (List)list;
  
          } else {
              throw new IllegalStateException(MessageBuilder.create("validation.notSupportType")
                      .var("property", getFieldPath())
                      .varWithClass("type", fieldType)
                      .format());
          }
  
      }
docs: フィールドの値をリストに変換して取得する。
  @return