Sstalle\php7cc\NodeVisitor\DuplicateFunctionParameterVisitor::enterNode PHP Метод

    public function enterNode(Node $node)
    {
        if (!$node instanceof Node\FunctionLike) {
            return;
        }
        $parametersNames = array();
        foreach ($node->getParams() as $parameter) {
            $currentParameterName = $parameter->name;
            if (!isset($parametersNames[$currentParameterName])) {
                $parametersNames[$currentParameterName] = false;
            } elseif (!$parametersNames[$currentParameterName]) {
                $this->addContextMessage(sprintf('Duplicate function parameter name "%s"', $currentParameterName), $node);
                $parametersNames[$currentParameterName] = true;
            }
        }
    }