Is collection empty, and all of its elements are empty

 
import java.util.Collection;
import java.util.Iterator;

public class Utils {

  public static <T> boolean isEmpty(Collection<T> c) {
    if (c == null || c.size() == 0) {
        return true;
    }
    for (Iterator<T> iter = c.iterator(); iter.hasNext();) {
        if (iter.next() != null) {
            return false;
        }
    }
    return true;
  }


}