private function setShadowAngle($angle)
    {
        if ($angle !== null) {
            $this->shadowProperties['direction'] = (string) $this->getExcelPointsAngle($angle);
        }

        return $this;
    }
private function setShadowAngle($angle)
    {
        if ($angle !== null) {
            $this->shadowProperties['direction'] = (string) $this->getExcelPointsAngle($angle);
        }

        return $this;
    }
private function setShadowAngle ( $ angle ) { if ( $ angle !== null ) { $ this -> shadowProperties [ 'direction' ] = ( string ) $ this -> getExcelPointsAngle ( $ angle ) ; } return $ this ; }
Set Shadow Angle

@param int $angle

@return PHPExcel_Chart_Axis
Set Shadow Angle