public static String chord(CharSequence... value) {
    StringBuilder builder = new StringBuilder();

    for (CharSequence seq : value) {
      builder.append(seq);
    }

    builder.append(Keys.NULL);
    return builder.toString();
  }
Simulate pressing many keys at once in a "chord".  Takes a sequence of Keys.XXXX or strings;
appends each of the values to a string, and adds the chord termination key (Keys.NULL) and
returns the resultant string.

Note: When the low-level webdriver key handlers see Keys.NULL, active modifier keys
(CTRL/ALT/SHIFT/etc) release via a keyup event.

Issue: http://code.google.com/p/webdriver/issues/detail?id=79
selendroid-server/src/main/java/io/selendroid/server/android/Keys.java