src/Log.php
public static function err($message, array $extras = [])
    {
        if (self::$logger) {
            self::$logger->err($message, $extras);
        }
    }
public static function err($message, array $extras = [])
    {
        if (self::$logger) {
            self::$logger->err($message, $extras);
        }
    }
public static function err ( $ message , array $ extras = [ ] ) { if ( self :: $ logger ) { self :: $ logger -> err ( $ message , $ extras ) ; } }
Log an error message for external consumption.

@param string $message
@param array  $extras

@return void
@throws \Zend\Log\Exception\InvalidArgumentException
@throws \Zend\Log\Exception\RuntimeException
Log an error message for external consumption .