-- ../../../../../Macaulay2/m2/methods.m2:481 addHook (HashTable,Thing,Function) := (obj,key,hook) -> (c := obj.cache; c#key = if c#?key then prepend(hook,c#key) else {hook}) -- ../../../../../Macaulay2/m2/methods.m2:477 addHook (MutableHashTable,Thing,Function) := (obj,key,hook) -> obj#key = if obj#?key then prepend(hook,obj#key) else {hook}