activity/object/object.php
public function setAuthor($author)
    {
        if (!is_null($author) && !$author instanceof ComActivitiesActivityObjectInterface) {
            throw new InvalidArgumentException('Invalid author type.');
        }

        $this->author = $author;
        return $this;
    }
public function setAuthor($author)
    {
        if (!is_null($author) && !$author instanceof ComActivitiesActivityObjectInterface) {
            throw new InvalidArgumentException('Invalid author type.');
        }

        $this->author = $author;
        return $this;
    }
public function setAuthor ( $ author ) { if ( ! is_null ( $ author ) && ! $ author instanceof ComActivitiesActivityObjectInterface ) { throw new InvalidArgumentException ( 'Invalid author type.' ) ; } $ this -> author = $ author ; return $ this ; }
Set the author.

@link http://activitystrea.ms/specs/json/1.0/#object See author property.

@param ComActivitiesActivityObjectInterface|null $author The author.
@return ComActivitiesActivityObject
Set the author .