NetworkServiceMock where responses can be defined before they are consumed

[ch-one]

In some situations it would be helpful to have a NetworkServiceMock where mocked responses can be defined before they are consumed.

Having an additional mock would bring the following benefits:

• Separation of mock setup and test code
• Response definition can be located in one place (in the beginning of the test method or in setUp method) and is not scattered
• Cases where it is not clear, when the network call will happen are no longer a problem
• Freedom of choice: Current NetworkServiceMock is still available

In addition the possibility to define a timing behaviour may be interesting. Something like:

• Immediately
• Delayed (by amount of time)