code: protected Object prepareYourCollection(VirtualForm virtualForm, Object bean, String name, Object value, StringBuilder pathSb,
              FormMappingOption option, PropertyDesc pd) {
          final List<FormYourCollectionResource> yourCollections = option.getYourCollections();
          if (yourCollections.isEmpty()) {
              return null; // no settings of your collections
          }
          final Class<?> propertyType = pd.getPropertyType();
          for (FormYourCollectionResource yourCollection : yourCollections) {
              if (!propertyType.equals(yourCollection.getYourType())) { // just type in form mapping (to avoid complexity)
                  continue;
              }
              final List<?> objectList = prepareObjectList(virtualForm, bean, name, value, pathSb, option, pd);
              final Iterable<? extends Object> applied = yourCollection.getYourCollectionCreator().apply(objectList);
              final Object mappedValue;
              if (applied instanceof List<?>) {
                  mappedValue = applied;
              } else {
                  final List<Object> newList = new ArrayList<>();
                  for (Object element : applied) {
                      newList.add(element);
                  }
                  mappedValue = newList;
              }
              return mappedValue;
          }
          return null; // is not your collections
      }
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