This program:

import java.util.ArrayList;
import java.util.List;

 class X {
        @SafeVarargs
        static void m(List<String>... ls) {
                Object[] o = ls; // 2 warning here
                o[0] = new ArrayList<Integer>();
                System.out.println(o);
        }
} 


Generates two 'varargs' warnings when compiled with the -Xlint:varargs flag enabled.

OUTPUT:

Test.java:7: warning: [varargs] Varargs method could cause heap pollution from non-reifiable varargs parameter ls
                Object[] o = ls; // 2 warning here
                             ^
Test.java:7: warning: [varargs] Varargs method could cause heap pollution from non-reifiable varargs parameter ls
                Object[] o = ls; // 2 warning here
                             ^
2 warnings