public static Vector padLeft(Collection strings) {
    Vector v = new Vector();
    int length = maxLength(strings);
    for (final Object o : strings) {
      String string = (String) o;
      v.add(padLeft(string, length));
    }
    return v;
  }
Centers the given string on the <code>PrintWriter</code>

@param s the string to center
@param pw the <code>PrintWriter</code> to print with
geode-junit/src/main/java/perffmwk/Formatter.java