Method setSubject

/**
 * Setter for the subject argument
 *
 * @param   TableInterface  $value  The value to set
 *
 * @return  TableInterface
 *
 * @throws  BadMethodCallException  If the argument is not of the expected type.
 */
protected function setSubject($value)
{
    if (!\is_object($value) || !$value instanceof TableInterface) {
        throw new BadMethodCallException("Argument 'subject' of event {$this->name} is not of the expected type");
    }
    return $value;
}