var SwiftTransformStream = require('swift-transform').Transform;
 
function MyTransformStream() {
    SwiftTransformStream.call(this, { objectMode: true, concurrency: 5 });
}
 
util.inherits(MyTransformStream, SwiftTransformStream);
 
// ------------------------------------
 
MyTransformStream.prototype._transform = function (data, encoding, callback) {
    // ..
};
 
MyTransformStream.prototype._flush = function (callback) {
    // ..
};
 
module.exports = MyTransformStream;

var swiftTransform = require('swift-transform');
 
readableStream
.pipe(swiftTransform(transformStream, 10))
.pipe(writableStream);