public function getImagePath(Image $file, $sizeName = null)
	{
		if ( ! $file instanceof Image) {
			throw new Exception\RuntimeException('Image entity expected');
		}

		$path = $this->getFilesystemDir($file);
		$size = $file->findImageSize($sizeName);
				
		if ($size instanceof ImageSize) {
			$path .= self::RESERVED_DIR_SIZE 
					. DIRECTORY_SEPARATOR
					. $size->getFolderName() 
					. DIRECTORY_SEPARATOR;
		}

		$path .= $file->getRealFileName();

		return $path;
	}