///|
pub extend Value with Eq::{equal, not_equal}

///|
pub extend Value with @debug.Debug::{to_repr}

///|
pub extend Model with Eq::{equal, not_equal}

///|
pub extend Model with @debug.Debug::{to_repr}

///|
pub extend Operation with Eq::{equal, not_equal}

///|
pub extend Operation with @debug.Debug::{to_repr}

///|
pub extend History with Eq::{equal, not_equal}

///|
pub extend History with @debug.Debug::{to_repr}

///|
pub extend HistoryError with @debug.Debug::{to_repr}