docs: public void parseContext(Object contextLike) throws JsonLdError {
          Context context;
          if (api != null) {
              context = new Context(api.opts);
          } else {
              context = new Context();
          }
          // Context will do our recursive parsing and initial IRI resolution
          context = context.parse(contextLike);
          // And then leak to us the potential 'prefixes'
          final Map<String, String> prefixes = context.getPrefixes(true);
  
          for (final String key : prefixes.keySet()) {
              final String val = prefixes.get(key);
              if ("@vocab".equals(key)) {
                  if (val == null || isString(val)) {
                      setNamespace("", val);
                  } else {
                  }
              } else if (!isKeyword(key)) {
                  setNamespace(key, val);
                  // TODO: should we make sure val is a valid URI prefix (i.e. it
                  // ends with /# or ?)
                  // or is it ok that full URIs for terms are used?
              }
          }
      }