code: function(lines) {
  		while (lines.length) {
  			if (!lines[0].trim()) {
  				lines.splice(0, 1);
  			} else {
  				break;
  			}
  		}
  
  		while (lines.length) {
  			if (!lines[lines.length - 1].trim()) {
  				lines.pop();
  			} else {
  				break;
  			}
  		}
  
  		return lines;
  	}
docs: After importing HTML, the resulting Markdown often has empty lines at the beginning and end due to block start/end or elements that were ignored, etc. If these white spaces were intended it's not really possible to detect it, so simply trim them all so that the result is more deterministic and can be easily unit tested.