code: public Options putContext(String key, Object value) {
      context.put(key, value);
      return this;
    }
docs: Attach some additional context information. Unlike with {@link
  com.segment.analytics.Analytics#getAnalyticsContext()}, this only has effect for this call.
  
  @param key The key of the extra context data
  @param value The value of the extra context data
  @return This options object for chaining