docs: function getUserProfile (psid, fields) {
    return new Promise (async (resolve, reject) => {
      if (!psid) {
        reject('PSID required');
      }
  
      if (!Array.isArray(fields)) {
        reject('fields must be an array');
      }
  
      let request_options = {
        'path': '/' + psid,
        'qs': {'fields': fields.join(',')}
      };
  
      try {
        let response = await this.sendGraphRequest(request_options);
        resolve(response);
      } catch (e) {
        reject(e);
      }
    });
  }