@Test
public void testContainsNonWhitespace() {

    // positive tests
    assertTrue(StringHelper.containsNonWhitespace("asdf"));
    assertTrue(StringHelper.containsNonWhitespace("  asdf"));
    assertTrue(StringHelper.containsNonWhitespace("asdf  "));
    assertTrue(StringHelper.containsNonWhitespace("asdf  t\r"));
    assertTrue(StringHelper.containsNonWhitespace("hello world"));
    // negative tests
    assertFalse(StringHelper.containsNonWhitespace(null));
    assertFalse(StringHelper.containsNonWhitespace(""));
    assertFalse(StringHelper.containsNonWhitespace(" "));
    assertFalse(StringHelper.containsNonWhitespace("             "));
    assertFalse(StringHelper.containsNonWhitespace("  \t  \r"));
}