public final function isNearQuadratic( float $maxDifference = 0.15 ) : bool
   {

      if ( $this->isQuadratic() )
      {
         return true;
      }

      if ( $maxDifference >= 0.01 && $maxDifference <= 0.3 )
      {
         $diff = 1.0 + $maxDifference;
      }
      else
      {
         $diff = 1.15;
      }

      if ( $this->isPortrait() )
      {
         return ( ( 0.0 + $this->_height ) / $this->_width ) <= $diff;
      }

      return ( ( 0.0 + $this->_width ) / $this->_height ) <= $diff;

   }