docs: function CalculatorPageObject() {
      var m = this[MODEL] = {};
  
      // Add directive to module.
      angular.module('testApp', [])
          .directive('calculator', calculatorDirective);
  
      // Create test context.
      var testContext = new AngularTestContext('testApp');
  
      // Compile and find elements.
      var element = testContext.compile('<calculator></calculator>');
  
      var inputs = element.find('input');
      expect(inputs.length).toBe(2);
  
      var button = element.find('button');
      expect(button.length).toBe(1);
  
      var result = element.find('span span');
      expect(result.length).toBe(1);
  
      m.input1 = $(inputs[0]);
      m.input2 = $(inputs[1]);
      m.button = button;
      m.result = result;
  }