docs: public static Object fromRDF(Object dataset, JsonLdOptions options) throws JsonLdError {
          // handle non specified serializer case
  
          RDFParser parser = null;
  
          if (options.format == null && dataset instanceof String) {
              // attempt to parse the input as nquads
              options.format = JsonLdConsts.APPLICATION_NQUADS;
          }
  
          if (rdfParsers.containsKey(options.format)) {
              parser = rdfParsers.get(options.format);
          } else {
              throw new JsonLdError(JsonLdError.Error.UNKNOWN_FORMAT, options.format);
          }
  
          // convert from RDF
          return fromRDF(dataset, options, parser);
      }