Imandrakit_error.DataExtensible data for errors.
Errors can contain arbitrary metadata in each level of its context, ie each message (as long as the metadata is serializable and printable).
module Twine = Imandrakit_twinemodule Key : sig ... endtype 'a key = 'a Key.tval to_twine : t Imandrakit_twine.Encode.encoderval of_twine : t Imandrakit_twine.Decode.decoderval empty : tEmpty set of data
val is_empty : t -> boolIs there nothing in the set?