Compiling "Spark::Block::Validates::WithValidators" fails due to unknown bare word `SparkFormFieldValidator`

[kentfredric]

Bareword "SparkFormFieldValidator" not allowed while "strict subs" in use at lib/Spark/Block/Validates/WithValidators.pm line 22.

https://github.com/perl-spark/Spark/blob/master/lib/Spark/Block/Validates/WithValidators.pm#L13

has _validators => (
    isa => ArrayRef [SparkFormFieldValidator],  ###
    is => 'rw',
    default => sub { [] },
    traits  => ['Array'],
    handles => {
        'validators' => 'elements',
    },
);