How can this program allow two class A implements Foo

package test1;

interface Foo {
       int bar();
       }
      
       public class Beta {
      
       class A implements Foo {
       public int bar() { return 1; }
       }
      
       public int fubar( Foo foo ) { return foo.bar(); }
      
       public void testFoo() {
      
       class A implements Foo {
       public int bar() { return 2; }
       }
       System.out.println( fubar( new A() ) );
       }
      
       public static void main( String[] argv ) {
       new Beta().testFoo();
       }
       }