NodaPatternConverter for Instant with numeric (unix) format in 2.x.x

As I can read on https://nodatime.org/2.0.x/userguide/migration-to-2 the support for numeric formatting of Instants has been removed.

Is there currently a way to create a NodaPatternConverter that will convert to a unix / ticks format and back?

SystemClock.Instance.GetCurrentInstant().ToString( "d", CultureInfo.InvariantCulture );

Results in the following exception:

NodaTime.Text.InvalidPatternException : The standard format "d" is not valid for the NodaTime.Instant type.

The solution based on Jon's suggestion I've ended up implementing:

public class InstantUnixTicksConverter : NodaConverterBase<Instant>
{
    protected override Instant ReadJsonImpl( JsonReader reader, JsonSerializer serializer )
    {
        string text = reader.Value.ToString();

        if ( !long.TryParse( text, out var ticks ) )
        {
            throw new InvalidNodaDataException( $"Value \'{text}\'cannot be parsed as numeric format {reader.TokenType}." );
        }

        return Instant.FromUnixTimeTicks( ticks );
    }

    protected override void WriteJsonImpl( JsonWriter writer, Instant value, JsonSerializer serializer )
    {
        writer.WriteValue( value.ToUnixTimeTicks() );
    }
}