index.js
function concat(res, done) {
  const chunks = []
  res
    .on('data', chunk => {
      chunks.push(chunk)
    })
    .on('end', () => {
      done(Buffer.concat(chunks))
    })
}
function concat(res, done) {
  const chunks = []
  res
    .on('data', chunk => {
      chunks.push(chunk)
    })
    .on('end', () => {
      done(Buffer.concat(chunks))
    })
}
function concat ( res , done ) { const chunks = [ ] res . on ( 'data' , chunk => { chunks . push ( chunk ) } ) . on ( 'end' , ( ) => { done ( Buffer . concat ( chunks ) ) } ) }
Buffer the entire stream into memory.
Buffer the entire stream into memory .