prototypal_extension.js

function Life(medium){
    this.medium=medium;
}
Life.prototype.eat=function(){return `get food from ${this.medium}`};


function Human(identity,medium){
     Object.setPrototypeOf(Human,Life);  
     Life.call(this,medium);
     this.identity=identity;  
}

Human.prototype=Object.assign(Object.create(Life.prototype),{constructor:Human});

var developer=new Human('coder','soil');
developer.eat(); //@returns "get food from soil"