public function setLevel($level)
    {
        if (false === Numeric::isPositiveInteger($level, false)) {
            throw new InvalidArgumentException('A nested level must be a positive integer.');
        }
        $this->_level = $level;
        return $this;
    }
public function setLevel($level)
    {
        if (false === Numeric::isPositiveInteger($level, false)) {
            throw new InvalidArgumentException('A nested level must be a positive integer.');
        }
        $this->_level = $level;
        return $this;
    }
public function setLevel ( $ level ) { if ( false === Numeric :: isPositiveInteger ( $ level , false ) ) { throw new InvalidArgumentException ( 'A nested level must be a positive integer.' ) ; } $ this -> _level = $ level ; return $ this ; }
Sets the level.

@param  integer              $level

@return Page
@throws InvalidArgumentException                 Raises if the value can not be cast to positive integer.
Sets the level .