code: function _createBlob(parts, properties) {
  	        parts = parts || [];
  	        properties = properties || {};
  
  	        try {
  	            return new Blob(parts, properties);
  	        } catch (err) {
  	            if (err.name !== 'TypeError') {
  	                throw err;
  	            }
  
  	            var BlobBuilder = globalObject.BlobBuilder || globalObject.MSBlobBuilder || globalObject.MozBlobBuilder || globalObject.WebKitBlobBuilder;
  
  	            var builder = new BlobBuilder();
  	            for (var i = 0; i < parts.length; i += 1) {
  	                builder.append(parts[i]);
  	            }
  
  	            return builder.getBlob(properties.type);
  	        }
  	    }
docs: Abstracts constructing a Blob object, so it also works in older browsers that don't support the native Blob constructor. (i.e. old QtWebKit versions, at least).