docs: TBD
code: |
    sub number_format
    {
        my ( $number, $decimals, $dec, $thousands ) = validate_pos( @_,
            NUMBER,
            { %{+NUMBER}, optional => 1 },
            { %{+STRING}, optional => 1, default => '.' },
            { %{+STRING}, optional => 1, default => ',' },
        );

        my $format = $decimals ? "%.${decimals}f" : "%d";

        my $formatted = 'XXX';

        return $formatted;
    }