text: var VIDEOS = {
  	'video 1': {
  		'': {
  			comments: [
  				{ id: 'page 1 comment 1' },
  				{
  					id: 'page 1 comment 2',
  					replies: [
  						{ id: 'page 1 comment 2 reply 1' },
  						{ id: 'page 1 comment 2 reply 2' }
  					]
  				},
  				{
  					id: 'page 1 comment 3',
  					replies: [
  						{ id: 'page 1 comment 3 reply 1' },
  						{ id: 'page 1 comment 3 reply 2' },
  						{ id: 'page 1 comment 3 reply 3' }
  					]
  				},
  				{ id: 'page 1 comment 4' },
  				{ id: 'page 1 comment 5' }
  			],
  			nextPageToken: 'page 2'
  		},
  		'page 2': {
  			comments: [
  				{ id: 'page 2 comment 1' },
  				{ id: 'page 2 comment 2' },
  				{ id: 'page 2 comment 3' }
  			]
  			// no nextPageToken
  		}
  	}
  };
  
  var ERROR_OBJECT = { type: 'video error', message: 'some error' };
  
  function fetchCommentsPage(videoId, nextPageToken) {
  	var video = VIDEOS[videoId];
  	var page;
  
  	if (!video) {
  		return Promise.reject(ERROR_OBJECT);
  	}
  
  	// NOTE: no token or an invalid token returns first comments page
  	page = video[nextPageToken] || video[''];
  
  	return Promise.resolve(page);
  }
  
  module.exports = fetchCommentsPage;
  