title: Unity - Inject different classes for the same interface
body: <p>I have one interface: <code>IFoo</code><br>
  Two classes implementing that interface: <code>FooOne</code> and <code>FooTwo</code><br>
  And two classes <code>ClassOne</code> and <code>ClassTwo</code> receiving an <code>IFoo</code> parameter in the constructor.  </p>
  
  <p>How I configure unity so <code>ClassOne</code> receives a <code>FooOne</code> instance and <code>ClassTwo</code> receives a <code>FooTwo</code> using only one container?</p>
  
  <p>I can't do it at runtime so it must be in the config file.</p>