code: public CustomEmoji getKnownCustomEmojiOrCreateCustomEmoji(JsonNode data) {
          long id = Long.parseLong(data.get("id").asText());
          CustomEmoji emoji = customEmojis.get(id);
          return emoji == null ? new CustomEmojiImpl(this, data) : emoji;
      }
docs: Gets a known custom emoji or creates a new (unknown) custom emoji object.
  
  @param data The data of the emoji.
  @return The emoji for the given json object.