return method reference of object that created inside the method

Question

i'm trying to understand some scenario i ran into related to method-reference. i have a method that create an object and then return a method reference based on that object. when the function ends, and i'm using this method reference outside , the response corresponds to the object that was created inside the method. wasn't it was supposed to be deleted by the garbage collector? how come i can still see it after the method ends?

import java.util.function.Function;

public class A {
    public String str;
    public A(){}
    public A(String str){
        this.str = str;
    }

    public String print(String msg) {
        return msg + " " + this.str;
    }
    public Function<String, String> func(){
        A a = new A("cat");
        return a::print;
    }

    public static void main(String[] args) {
        A a1 = new A();
        Function<String, String> foo = a1.func();
        System.out.println(foo.apply("animals: "));
    }
}

the output is:

animals:  cat

i expected some error, not "cat".