code: function (details, callback) {
      var self = this;
  
      ['contentType', 'contents'].forEach(function (required) {
        if (!details[required]) {
          throw new Error('details.' + required + ' is a required argument.');
        }
      });
  
      if (details.contentType !== 'BIND_9') {
        callback(new Error({ invalidRequest: true }));
        return;
      }
  
      var importedZone = {
        contentType: details.contentType,
        contents: details.contents
      };
  
      var requestOptions = {
        path: urlJoin(_urlPrefix, 'import'),
        method: 'POST',
        body: {
          domains: [
            importedZone ]
        }
      };
  
      self._asyncRequest(requestOptions, function (err, result) {
        return err
          ? callback(err)
          : callback(err, result.response.domains.map(function (domain) {
          return new dns.Zone(self, domain);
        })[0]);
      });
    }
docs: @name Client.importZone
  
  @description This call provisions a new DNS zone under the account
  specified by the BIND 9 formatted file configuration contents defined
  in the request object.
  
  @param {Object}     details     the information for your new zone
  @param {Function}   callback    handles the callback of your api call