#[derive(Debug, thiserror::Error)]
pub(crate) enum Error {
#[error("a change referenced an actor index we couldn't find")]
MissingActor,
#[error("changes out of order")]
ChangesOutOfOrder,
#[error("incorrect max op")]
InvalidState,
#[error("invalid internal state")]
IncorrectMaxOp,
#[error("missing ops")]
MissingOps,
#[error("missing ops")]
MissingDep(#[from] crate::change_graph::MissingDep),
}