@Test
public void isNumeric() {

    assertTrue(NumberHelper.isNumeric("1"));
    assertTrue(NumberHelper.isNumeric("935"));
    assertTrue(NumberHelper.isNumeric("a13"));
    assertTrue(NumberHelper.isNumeric("7B"));
    assertTrue(NumberHelper.isNumeric("as782u"));
    assertTrue(NumberHelper.isNumeric("1-2"));
    assertTrue(NumberHelper.isNumeric("42-0815,47&11"));
    assertTrue(NumberHelper.isNumeric("42 -   0815 , 47   & 11"));
    assertTrue(NumberHelper.isNumeric("42a -  tt0815 ,  ll47uu &o11"));
    assertFalse(NumberHelper.isNumeric("a"));
    assertFalse(NumberHelper.isNumeric("a-z"));
    assertFalse(NumberHelper.isNumeric("5-a"));
}