text: // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  'use strict';
  require('../common');
  const Readable = require('stream').Readable;
  const assert = require('assert');
  
  const s = new Readable({
    highWaterMark: 20,
    encoding: 'ascii'
  });
  
  const list = ['1', '2', '3', '4', '5', '6'];
  
  s._read = function(n) {
    const one = list.shift();
    if (!one) {
      s.push(null);
    } else {
      const two = list.shift();
      s.push(one);
      s.push(two);
    }
  };
  
  s.read(0);
  
  // ACTUALLY [1, 3, 5, 6, 4, 2]
  
  process.on('exit', function() {
    assert.deepStrictEqual(s._readableState.buffer.join(','), '1,2,3,4,5,6');
    console.log('ok');
  });
  