Store the name of the class.
Manage and deserial boolean fields from input form
multiClean( $value) : array
Multi-clean a value.
If you are getting multiple values, you need to go through all of them and validate them against the requirements. This will do that for you. Basically, it is cloning the field, marking it as not multiple and validate each value. It will throw an exception in case of failure.
If you are implementing your own field which could be filled by a "multiple" widget, you need to perform a check on $this->multiple.