text: import stream from 'readable-stream'
  
  import { patchTransform } from './internal/concurrency'
  import { handlePromise } from './internal/promise'
  import { inherits } from './internal/util'
  
  export function Transform (options) {
    if (!(this instanceof Transform)) {
      return new Transform(options)
    }
    stream.Transform.call(this, options)
    this._transform = handlePromise(this._transform)
    this._flush = handlePromise(this._flush)
    this._destroy = handlePromise(this._destroy)
    if (options && options.concurrency >= 2) {
      patchTransform(this, options.concurrency)
    }
  }
  
  inherits(Transform, stream.Transform)
  