src/Airbrake/EventFilter/Error/ErrorReporting.php
public function shouldSendError($type, $message, $file = null, $line = null, $context = null)
    {
        $level = $this->config->get('errorReportingLevel');
        if (-1 == $level) {
            return true;
        }

        return $level & $type;
    }
public function shouldSendError($type, $message, $file = null, $line = null, $context = null)
    {
        $level = $this->config->get('errorReportingLevel');
        if (-1 == $level) {
            return true;
        }

        return $level & $type;
    }
Filters out PHP errors before they get sent

@param int $type
@param string $message
@param string $file
@param int $line
@param array $context
@see http://us3.php.net/manual/en/function.set-error-handler.php
@return bool