### Question:
LeftSideZerosFormatter implements Formatter { @Override public boolean isFormatted(String value) { return value.matches("\\d{" + formattedLength + "}"); } LeftSideZerosFormatter(int formattedLength); @Override String format(String value); @Override String unformat(String value); @Override boolean isFormatted(String value); @Override boolean canBeFormatted(String value);  }### Answer:
@Test public void shouldVerifyIfAValueIsAlreadyFormattedOrNot() throws Exception { assertTrue(formatter.isFormatted("00001234567890")); assertFalse(formatter.isFormatted("00001234")); assertFalse(formatter.isFormatted("1234567890")); assertFalse(formatter.isFormatted("123456789012345")); }