code: function(serviceName, creator) {
  
  			if (typeof services[serviceName] !== 'undefined') {
  				error(new Error('Service ' + serviceName + ' has already been added.'));
  				return this;
  			}
  
  			services[serviceName] = {
  				creator: creator,
  				instance: null
  			};
  
  			return this;
  		}
docs: ---------------------------------------------------------------------- Service-Related ---------------------------------------------------------------------- 
  Registers a new service
  @param {string} serviceName Unique service identifier
  @param {Function} creator Factory function used to generate the service
  @returns {Box.Application} The application object.
  @throws {Error} If a service has already been added