old_contents: describe('sandbox library - TV4', function () {
      this.timeout(1000 * 60);
      var Sandbox = require('../../../'),
          context;
  
      beforeEach(function (done) {
          Sandbox.createContext({}, function (err, ctx) {
              context = ctx;
              done(err);
          });
      });
  
      afterEach(function () {
          context.dispose();
          context = null;
      });
  
      it('must exist', function (done) {
          context.execute(`
              var assert = require('assert');
  
              assert.strictEqual(typeof tv4, 'object', 'typeof tv4 must be object');
              assert.strictEqual(typeof tv4.validate, 'function', 'typeof tv4.validate must be function');
          `, done);
      });
  
      it('must have basic functionality working', function (done) {
          context.execute(`
              var assert = require('assert'),
                  schema = {
                      "$schema": "http://json-schema.org/draft-04/schema#",
                      "type": "object",
                      "properties": {
                          "alpha": {
                              "type": "boolean"
                          }
                      }
                  };
  
              assert(tv4.validate({alpha: true}, schema), 'TV4 schema validation must identify valid objects');
          `, done);
      });
  });
  
new_contents: describe('sandbox library - TV4', function () {
      this.timeout(1000 * 60);
      var Sandbox = require('../../../'),
          context;
  
      beforeEach(function (done) {
          Sandbox.createContext({}, function (err, ctx) {
              context = ctx;
              done(err);
          });
      });
  
      afterEach(function () {
          context.dispose();
          context = null;
      });
  
      it('should exist', function (done) {
          context.execute(`
              var assert = require('assert');
  
              assert.strictEqual(typeof tv4, 'object', 'typeof tv4 must be object');
              assert.strictEqual(typeof tv4.validate, 'function', 'typeof tv4.validate must be function');
          `, done);
      });
  
      it('should have basic functionality working', function (done) {
          context.execute(`
              var assert = require('assert'),
                  schema = {
                      "$schema": "http://json-schema.org/draft-04/schema#",
                      "type": "object",
                      "properties": {
                          "alpha": {
                              "type": "boolean"
                          }
                      }
                  };
  
              assert(tv4.validate({alpha: true}, schema), 'TV4 schema validation must identify valid objects');
          `, done);
      });
  });
  
subject: Change must to should