text: define("optional", function factory() {
  	// We have to use a factory function with "return" so that semver-sync
  	// picks up the version number when it checks or bumps.
  	return {
  		version: "0.1.0",
  
  		// The array of failed loads.
  		failed: [],
  
  		load: function load(name, req, onLoad, _config) {
  			if (name.length !== 0) {
  				req([name], onLoad, function failed() {
  					this.failed.push(name);
  					// Undef exists only on the global require, not local ones.
  					requirejs.undef(name);
  
  					// We do not *define* the module but just return a default value for
  					// it. This ensures isolation between calls that require the same
  					// module, sometimes optionally, sometimes not.
  					onLoad({});
  				}.bind(this));
  			} else {
  				onLoad(this);
  			}
  		},
  	};
  });
  