public static String trimToNull(CharSequence str) {
		final String trimStr = trim(str);
		return EMPTY.equals(trimStr) ? null : trimStr;
	}
@Test
	public void trimToNullTest(){
		String a = "  ";
		assertNull(CharSequenceUtil.trimToNull(a));

		a = "";
		assertNull(CharSequenceUtil.trimToNull(a));

		a = null;
		assertNull(CharSequenceUtil.trimToNull(a));
	}