index.js
function setWriteHeadHeaders (statusCode) {
  var length = arguments.length
  var headerIndex = length > 1 && typeof arguments[1] === 'string'
    ? 2
    : 1

  var headers = length >= headerIndex + 1
    ? arguments[headerIndex]
    : undefined

  this.statusCode = statusCode

  if (Array.isArray(headers)) {
    // handle array case
    setHeadersFromArray(this, headers)
  } else if (headers) {
    // handle object case
    setHeadersFromObject(this, headers)
  }

  // copy leading arguments
  var args = new Array(Math.min(length, headerIndex))
  for (var i = 0; i < args.length; i++) {
    args[i] = arguments[i]
  }

  return args
}
function setWriteHeadHeaders (statusCode) {
  var length = arguments.length
  var headerIndex = length > 1 && typeof arguments[1] === 'string'
    ? 2
    : 1

  var headers = length >= headerIndex + 1
    ? arguments[headerIndex]
    : undefined

  this.statusCode = statusCode

  if (Array.isArray(headers)) {
    // handle array case
    setHeadersFromArray(this, headers)
  } else if (headers) {
    // handle object case
    setHeadersFromObject(this, headers)
  }

  // copy leading arguments
  var args = new Array(Math.min(length, headerIndex))
  for (var i = 0; i < args.length; i++) {
    args[i] = arguments[i]
  }

  return args
}
function setWriteHeadHeaders ( statusCode ) { var length = arguments . length var headerIndex = length > 1 && typeof arguments [ 1 ] === 'string' ? 2 : 1 var headers = length >= headerIndex + 1 ? arguments [ headerIndex ] : undefined this . statusCode = statusCode if ( Array . isArray ( headers ) ) { // handle array case setHeadersFromArray ( this , headers ) } else if ( headers ) { // handle object case setHeadersFromObject ( this , headers ) } // copy leading arguments var args = new Array ( Math . min ( length , headerIndex ) ) for ( var i = 0 ; i < args . length ; i ++ ) { args [ i ] = arguments [ i ] } return args }
Set headers and other properties on the response object.

@param {number} statusCode
@private
Set headers and other properties on the response object .