/* SOME REUSABLE MODULE. */

class MyLib {

	constructor( apiKey = process.env.MY_LIB_API_KEY ) {

		this.apiKey = apiKey;

	}

	inspect() {

		return( `API KEY: ${ this.apiKey }` );

	}

}

// ----------------------------------------------------------------------------------- //
// ----------------------------------------------------------------------------------- //

/* THE APPLICATION BOOTSTRAPPING PROCESS. */

// Notice that when the application instantiates the MyLib() class, it doesn't provide
// an explicit constructor argument. Instead, it allows the target module to fall-back
// to the GLOBAL STATE represented in the "process.env" object.
var myLib = new MyLib();

console.log( myLib.inspect() );