code: public Yoke set(@NotNull String key, Object value) {
          if (value == null) {
              defaultContext.remove(key);
          } else {
              defaultContext.put(key, value);
          }
  
          return this;
      }
docs: When you need to share global properties with your requests you can add them
  to Yoke and on every request they will be available as request.get(String)
  
  @param key   unique identifier
  @param value Any non null value, nulls are not saved