altMasks property
this field is used for those countries there there is more than one possible masks e.g. Brazil. In most cases this field is null IMPORTANT! all masks MUST be placed in an ascending order e.g. the shortest possible mask must be placed in a phoneMask variable, the longer ones must be in altMasks list starting from the shortest. That's because they are checked in a direct order on a user input
Implementation
final List<String>? altMasks;