public function getExpression($part = null)
    {
        if (null === $part) {
            return implode(' ', $this->cronParts);
        } elseif (array_key_exists($part, $this->cronParts)) {
            return $this->cronParts[$part];
        }

        return null;
    }
public function getExpression($part = null)
    {
        if (null === $part) {
            return implode(' ', $this->cronParts);
        } elseif (array_key_exists($part, $this->cronParts)) {
            return $this->cronParts[$part];
        }

        return null;
    }
public function getExpression ( $ part = null ) { if ( null === $ part ) { return implode ( ' ' , $ this -> cronParts ) ; } elseif ( array_key_exists ( $ part , $ this -> cronParts ) ) { return $ this -> cronParts [ $ part ] ; } return null ; }
Get all or part of the CRON expression

@param string $part Specify the part to retrieve or NULL to get the full
cron schedule string.

@return string|null Returns the CRON expression, a part of the
CRON expression, or NULL if the part was specified but not found
Get all or part of the CRON expression