src/Validator/Validator.php
public function addRule($index, $method = null, ...$params)
    {
        $this->rules[$index] = [$method, $params];
        return $this;
    }
public function addRule($index, $method = null, ...$params)
    {
        $this->rules[$index] = [$method, $params];
        return $this;
    }
public function addRule ( $ index , $ method = null , ... $ params ) { $ this -> rules [ $ index ] = [ $ method , $ params ] ; return $ this ; }
Add a single rule to the rules container

@param $index
@param $rule
@return $this
Add a single rule to the rules container