old_contents: "use strict";
  
  exports.tryCatch = function (done, func) {
    try {
      func();
      done();
    } catch (err) {
      done(err);
    }
  };
  
new_contents: "use strict";
  
  var blessed = require("blessed");
  var contrib = require("blessed-contrib");
  
  exports.tryCatch = function (done, func) {
    try {
      func();
      done();
    } catch (err) {
      done(err);
    }
  };
  
  exports.getTestContainer = function (sandbox) {
    var mockScreen = {
      on: sandbox.stub(),
      append: sandbox.stub(),
      remove: sandbox.stub(),
      type: "screen",
      setEffects: sandbox.stub(),
      _events: {},
      clickable: [],
      keyable: [],
      rewindFocus: sandbox.stub(),
      _listenKeys: sandbox.stub(),
      _listenMouse: sandbox.stub()
    };
    var container = blessed.box({ parent: mockScreen });
    sandbox.stub(container, "render");
    return container;
  };
  
  // stub functions that require an active screen
  exports.stubWidgets = function (sandbox) {
    sandbox.stub(blessed.element.prototype, "setContent");
    sandbox.stub(blessed.element.prototype, "setLabel");
    sandbox.stub(contrib.line.prototype, "setData");
    sandbox.stub(contrib.gauge.prototype, "setData");
  };
  
subject: test util for creating mock container/screen