The `goog.testing.MethodMock` Namespace

`goog.testing.MethodMock(scope, functionName, opt_strictness)`

Mocks an existing function. Creates a goog.testing.FunctionMock and registers it in the given scope with the name specified by functionName.

scope {Object}: The scope of the method to be mocked out.
functionName {string}: The name of the function we're going to mock.
opt_strictness {number=}: One of goog.testing.Mock.LOOSE or goog.testing.Mock.STRICT. The default is STRICT.
returns {goog.testing.MockInterface}: The mocked method.

Resets the global function that we mocked back to its original state. @this {goog.testing.MockInterface}