async getCorrespondentNameById(correspondentId) {
    /**
     * Get the Name of a Correspondent by its ID.
     * 
     * @param   id  The id of the correspondent.
     * @returns    The name of the correspondent.
     */
    this.initialize();
    try {
      const response = await this.client.get(`/correspondents/${correspondentId}/`);
      return response.data;
    } catch (error) {
      console.error(`[ERROR] fetching correspondent ${correspondentId}:`, error.message);
      return null;
    }
  }
Get all Document IDs from the Paperless API.

@returns    An array of all Document IDs.
@throws     An error if the request fails.
@note       This method is used to get all Document IDs for further processing.