@Test
void toUpperCaseChar() {

    assertThat(ASCII.toUpperCase('-')).isEqualTo('-');
    assertThat(ASCII.toUpperCase('a')).isEqualTo('A');
    assertThat(ASCII.toUpperCase('z')).isEqualTo('Z');
    assertThat(ASCII.toUpperCase('0')).isEqualTo('0');
    assertThat(ASCII.toUpperCase('9')).isEqualTo('9');
    assertThat(ASCII.toUpperCase('A')).isEqualTo('A');
    assertThat(ASCII.toUpperCase('Z')).isEqualTo('Z');
}