https://arrow.apache.org/docs/dev/c_glib/arrow-glib/method.Decimal128ArrayBuilder.append.html
Arrow.Decimal128ArrayBuilder.append
arrowappend
https://arrow.apache.org/docs/dev/c_glib/arrow-glib/method.Decimal128ArrayBuilder.append_null.html
Arrow.Decimal128ArrayBuilder.append_null
arrowappendnull