docs: static void pruneBlankNodes(final Object input) {
          final Map<String, Object> toPrune = new HashMap<>();
          fillNodesToPrune(input, toPrune);
          for (final String id : toPrune.keySet()) {
              final Object node = toPrune.get(id);
              if (node == null) {
                  continue;
              }
              ((Map<String, Object>) node).remove(JsonLdConsts.ID);
          }
      }