Acceda a una función declarada dentro de una clase con esto.

class Person{
	 	
		constructor(name)
		 {
			 this.name = name;
			 this.say();
		 }
		 
		 /*notice the word function is missing*/
  /*think of say() as a static method...every instance of Person has it...and you use it with this.say() in Class Person*/
		  say()
		 {
		 	
			 alert("say");
		 }
	 }
Javasper