How to use the vega-dataflow.Tuple function in vega-dataflow

var dl = require('datalib'),
    log = require('vega-logging'),
    df = require('vega-dataflow'),
    Node = df.Node, // jshint ignore:line
    Tuple = df.Tuple,
    Deps = df.Dependencies;

var Types = {
  INSERT: "insert",
  REMOVE: "remove",
  UPSERT: "upsert",
  TOGGLE: "toggle",
  CLEAR:  "clear"
};

var EMPTY = [];

function filter(fields, value, src, dest) {
  if ((fields = dl.array(fields)) && !fields.length) {
    fields = dl.isObject(value) ? dl.keys(value) : ['data'];
  }

var dl = require('datalib'),
    df = require('vega-dataflow'),
    Node  = df.Node, // jshint ignore:line
    Deps  = df.Dependencies,
    Tuple = df.Tuple,
    Collector = df.Collector,
    log = require('vega-logging'),
    Builder = require('./Builder'),
    Scale = require('./Scale'),
    parseAxes = require('../parse/axes'),
    parseLegends = require('../parse/legends');

function GroupBuilder() {
  this._children = {};
  this._scaler = null;
  this._recursor = null;

  this._scales = {};
  this.scale = scale.bind(this);
  return arguments.length ? this.init.apply(this, arguments) : this;
}

var dl = require('datalib'),
    log = require('vega-logging'),
    Item = require('vega-scenegraph').Item,
    df = require('vega-dataflow'),
    Node = df.Node, // jshint ignore:line
    Deps = df.Dependencies,
    Tuple = df.Tuple,
    ChangeSet = df.ChangeSet,
    Sentinel = {},
    Encoder  = require('./Encoder'),
    Bounder  = require('./Bounder'),
    parseData = require('../parse/data');

function Builder() {
  return arguments.length ? this.init.apply(this, arguments) : this;
}

var Status = Builder.STATUS = {
  ENTER:  'enter',
  UPDATE: 'update',
  EXIT:   'exit'
};

var d3 = require('d3'),
    dl = require('datalib'),
    log = require('vega-logging'),
    Tuple = require('vega-dataflow').Tuple;

var DEPS = ["signals", "scales", "data", "fields"];

function properties(model, mark, spec) {
  var config = model.config(),
      code = "",
      names = dl.keys(spec),
      exprs = [], // parsed expressions injected in the generated code
      i, len, name, ref, vars = {},
      deps = {
        signals: {},
        scales:  {},
        data:    {},
        fields:  {},
        nested:  [],
        _nRefs:  {},  // Temp stash to de-dupe nested refs.

var df = require('vega-dataflow'),
    Tuple = df.Tuple,
    log = require('vega-logging'),
    Transform = require('./Transform');

function CountPattern(graph) {
  Transform.prototype.init.call(this, graph);
  Transform.addParameters(this, {
    field:     {type: 'field', default: 'data'},
    pattern:   {type: 'value', default: '[\\w\']+'},
    case:      {type: 'value', default: 'lower'},
    stopwords: {type: 'value', default: ''}
  });

  this._output = {text: 'text', count: 'count'};

  return this.router(true).produces(true);
}

var df = require('vega-dataflow'),
    Tuple = df.Tuple,
    log = require('vega-logging'),
    Transform = require('./Transform');

function Formula(graph) {
  Transform.prototype.init.call(this, graph);
  Transform.addParameters(this, {
    field: {type: 'value'},
    expr:  {type: 'expr'}
  });

  return this.mutates(true);
}

var prototype = (Formula.prototype = Object.create(Transform.prototype));
prototype.constructor = Formula;

var Tuple = require('vega-dataflow').Tuple,
    log = require('vega-logging'),
    Transform = require('./Transform'),
    BatchTransform = require('./BatchTransform');

function Rank(graph) {
  BatchTransform.prototype.init.call(this, graph);
  Transform.addParameters(this, {
    field: {type: 'field', default: null},
    normalize: {type: 'value', default: false}
  });

  this._output = {
    'rank': 'rank'
  };

  return this.mutates(true);

var dl = require('datalib'),
    Tuple = require('vega-dataflow').Tuple,
    log = require('vega-logging'),
    Transform = require('./Transform'),
    BatchTransform = require('./BatchTransform');

function Treeify(graph) {
  BatchTransform.prototype.init.call(this, graph);
  Transform.addParameters(this, {
    groupby: {type: 'array'}
  });

  this._output = {
    'children': 'children',
    'parent':   'parent'
  };
  return this.router(true).produces(true);
}

var d3 = require('d3'),
    bound = require('vega-scenegraph').bound,
    Tuple = require('vega-dataflow').Tuple,
    Status = require('./Builder').STATUS;

function Transition(duration, ease) {
  this.duration = duration || 500;
  this.ease = ease && d3.ease(ease) || d3.ease('cubic-in-out');
  this.updates = {next: null};
}

var prototype = Transition.prototype;

var skip = {
  'text': 1,
  'url':  1
};

prototype.interpolate = function(item, values) {

var dl = require('datalib'),
    Aggregator = dl.Aggregator,
    Base = Aggregator.prototype,
    df = require('vega-dataflow'),
    Tuple = df.Tuple,
    log = require('vega-logging'),
    facetID = 0;

function Facetor() {
  Aggregator.call(this);
  this._facet = null;
  this._facetID = ++facetID;
}

var prototype = (Facetor.prototype = Object.create(Base));
prototype.constructor = Facetor;

prototype.facet = function(f) {
  return arguments.length ? (this._facet = f, this) : this._facet;
};