src/Metable/Attribute.php
protected function getMutatedType($value, $dir = 'setter')
    {
        foreach ($this->{"{$dir}Mutators"} as $mutated => $mutator) {
            if ($this->getValueType($value) == $mutated || $value instanceof $mutated) {
                return $mutated;
            }
        }
    }
protected function getMutatedType($value, $dir = 'setter')
    {
        foreach ($this->{"{$dir}Mutators"} as $mutated => $mutator) {
            if ($this->getValueType($value) == $mutated || $value instanceof $mutated) {
                return $mutated;
            }
        }
    }
Get the mutated type.

@param  mixed  $value
@param  string $dir
@return string