docs: function(options, callback) {
          var self = this;
  
          ['flavor', 'size'].forEach(function(required) {
              if (!options[required]) throw new Error('options.' +
                  required + ' is a required argument.');
          });
  
          var requestOptions = {
              uri: '/instances',
              method: 'POST',
              data: {
                  instance: {
                      flavorRef: options.flavor,
                      volume: {size: options.size},
                  }
              },
              endpoint: rackspace.Endpoints.CloudDatabases
          };
  
          ['name', 'databases', 'users'].forEach(function(optional) {
              requestOptions.data.instance[optional] = options[optional];
          });
  
          self.authorizedRequest(requestOptions, function(err, res, body) {
              if (err || !body.instance) {
                  callback(err ? err : body);
                  return;
              }
  
              callback(err, new rackspace.DatabaseInstance(self, _.extend({}, body.instance, options)));
          });
      }