code: function getCustomLabelsByPsid (psid) {
    return new Promise (async (resolve, reject) => {
      if (!psid) {
        reject('PSID required');
      }
  
      let options = {
        'path': `/${psid}/custom_labels`
      };
  
      try {
        let response = await  this.callCustomLabelsApi(options);
        resolve(response);
      } catch (e) {
        reject(e);
      }
    });
  }
docs: Retrieves the list of custom labels associated with a PSID.
  @param  {Integer}  psid  The PSID of the user to retrieve the custom labels for.
  @return {Promise<Object>}  The API response
  @memberof  Client#
  @example
  Client.getCustomLabelsByPsid(950724069735075)
  .then(res => {
  console.log(res);
  // {
  //   "data": [
  //     { "name": "myLabel", "id": "1001200005003"},
  //     { "name": "myOtherLabel", "id": "1001200005002"}
  //   ],
  //   "paging": {
  //     "cursors": {
  //       "before": "QVFIUmx1WTBpMGpJWXprYzVYaVhabW55dVpyc",
  //       "after": "QVFIUmItNkpTbjVzakxFWGRydzdaVUFNNnNPaU"
  //     }
  //   }
  // }
  });