Overtrue\Validation\Validator::doReplacements PHP Method

    protected function doReplacements($message, $attribute, $rule, $parameters)
    {
        $value = $this->getAttribute($attribute);
        $message = str_replace([':ATTRIBUTE', ':Attribute', ':attribute'], [strtoupper($value), ucfirst($value), $value], $message);
        if (isset($this->replacers[snake_case($rule)])) {
            $message = $this->callReplacer($message, $attribute, snake_case($rule), $parameters);
        } elseif (method_exists($this, $replacer = "replace{$rule}")) {
            $message = $this->{$replacer}($message, $attribute, $rule, $parameters);
        }
        return $message;
    }