class Rat{ constructor(name){ this.name=name; this.rats=[]; } unite(rat){ if(rat instanceof Rat){ this.rats.push(rat); } }; getRats(){ return this.rats; } toString(){ let ratsNames=this.rats.map(x=>{ return `##${x.name}`; }); let result=`${this.name}${'\n'}${ratsNames.join('\n')}`; return result; } }