public function addInterface(string $interface) : bool
    {
        $retval = false;

        if (!array_search($interface, $this->interface_list)) {
            $this->interface_list[] = $interface;
            $retval = true;
        }

        return $retval;
    }
public function addInterface(string $interface) : bool
    {
        $retval = false;

        if (!array_search($interface, $this->interface_list)) {
            $this->interface_list[] = $interface;
            $retval = true;
        }

        return $retval;
    }
public function addInterface ( string $ interface ) : bool { $ retval = false ; if ( ! array_search ( $ interface , $ this -> interface_list ) ) { $ this -> interface_list [ ] = $ interface ; $ retval = true ; } return $ retval ; }
Add an interface to the class declaration. If interface already exists then the action is ignored
@param string $interface Name of interface to be added
@return bool Return true if $interface is added of false if it already exists
Add an interface to the class declaration . If interface already exists then the action is ignored