src/Javascript/ValidatorHandler.php
public function sometimes($attribute, $rules = [])
    {
        $callback = function () {
            return true;
        };
        $this->validator->sometimes($attribute, $rules, $callback);
        $this->rules->addConditionalRules($attribute, (array) $rules);
    }
public function sometimes($attribute, $rules = [])
    {
        $callback = function () {
            return true;
        };
        $this->validator->sometimes($attribute, $rules, $callback);
        $this->rules->addConditionalRules($attribute, (array) $rules);
    }
Validate Conditional Validations using Ajax in specified fields.

@param string $attribute
@param string|array $rules
@return void