public function addInvitation(Invitation $invitation): self
    {
        $invitation->setEvent($this);
        $this->invitations[] = $invitation;

        return $this;
    }
public function addInvitation(Invitation $invitation): self
    {
        $invitation->setEvent($this);
        $this->invitations[] = $invitation;

        return $this;
    }
public function addInvitation ( Invitation $ invitation ) : self { $ invitation -> setEvent ( $ this ) ; $ this -> invitations [ ] = $ invitation ; return $ this ; }
Add invitation.

@param Invitation $invitation The invitation.

@return Event
Add invitation .