src/Psr16Manager.php
public function logger(LoggerInterface $logger = null)
    {
        if (!is_null($logger)) {
            $this->_logger = $logger;
        }

        return $this->_logger;
    }
public function logger(LoggerInterface $logger = null)
    {
        if (!is_null($logger)) {
            $this->_logger = $logger;
        }

        return $this->_logger;
    }
日志.

@param \Psr\Log\LoggerInterface $logger 日志处理器

@return \Psr\Log\LoggerInterface