@Nonnull
	public static String cutOffAtFirst(@Nonnull String text, char cutoff) {
		int i = text.indexOf(cutoff);
		if (i < 0) return text;
		return text.substring(0, i);
	}
@Test
	void testCutOffAtFirst() {
		// chars
		assertEquals("", StringUtil.cutOffAtFirst("", 'd'));
		assertEquals("abc", StringUtil.cutOffAtFirst("abcdefg", 'd'));
		assertEquals("abc", StringUtil.cutOffAtFirst("abcdefgd", 'd'));
		// strings
		assertEquals("", StringUtil.cutOffAtFirst("", "d"));
		assertEquals("abc", StringUtil.cutOffAtFirst("abcdefg", "d"));
		assertEquals("abc", StringUtil.cutOffAtFirst("abcdefgd", "d"));
	}