public static String capitalize(String string) {
        return string == null ? null : string.substring( 0, 1 ).toUpperCase( Locale.ROOT ) + string.substring( 1 );
    }
@Test
    public void testCapitalize() {
        assertThat( Strings.capitalize( null ) ).isNull();
        assertThat( Strings.capitalize( "c" ) ).isEqualTo( "C" );
        assertThat( Strings.capitalize( "capitalize" ) ).isEqualTo( "Capitalize" );
        assertThat( Strings.capitalize( "AlreadyCapitalized" ) ).isEqualTo( "AlreadyCapitalized" );
        assertThat( Strings.capitalize( "notCapitalized" ) ).isEqualTo( "NotCapitalized" );
    }