code: @Deprecated
      public void initNesting() {
          boolean nested = setupManyNesting();
          if (!nested && shouldBeNested()) {
              setupOneNesting();
          }
          if (isNested()) {
              PreconditionUtil.verify(parentField.getOppositeName() != null,
                      "relationship between parent pointing to a nested resource must specify @JsonApiRelation.mappedBy or @JsonApiRelation.opposite, not "
                              + "found for '%s' of %s",
                      parentField.getUnderlyingName(), implementationClass);
          }
      }
docs: Hide with implementation/interface