This function doesn't appear to work at all. You have to create a new BCMath\Number object to use it, at which point it attempts to overwrite the value of said object - and of course that won't work because BCMath\Number::$value is readonly.
(PHP 8 >= 8.4.0)
BcMath\Number::__unserialize — Desserializa um parâmetro de dados em um objeto BcMath\Number
Desserializa um parâmetro de dados em um objeto BcMath\Number.
dataEste método lança uma exceção ValueError se dados serializados inválidos forem passados.
This function doesn't appear to work at all. You have to create a new BCMath\Number object to use it, at which point it attempts to overwrite the value of said object - and of course that won't work because BCMath\Number::$value is readonly.