code: function(publicKey, rules, callback) {
          if (!Array.isArray(rules)) {
              rules = [rules];
          }
  
          if (!publicKey) {
              throw new Error('Public key must be a valid string');
          }
  
          var url = this.getResourceUrl({ path: '/keys/' + publicKey + '/access', user: null });
  
          request({
              method: 'POST',
              uri: this.getSignedResourceUrl('POST', url),
              json: rules,
              onComplete: function(err, res, body) {
                  callback(err, body, res);
              }
          });
  
          return this;
      }
docs: Add one or more access control rules to the given public key
  
  @param {String} publicKey The public key to add rules to
  @param {Array} rules Array of access control rules to add
  @param {Function} callback
  @return {ImboClient}