what expression <>c__DisplayClass9 means in c#
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I've used decompiler to get the sources of some library in C#. One of unknown (to me) constructs it produced is the following:

    Action action = null;
    <>c__DisplayClass9 class2;
    action = new Action(class2, (IntPtr) this.<OptimizeVisuals>b__6);

Things like `<>c__DisplayClass9` or `(IntPtr) this.<OptimizeVisuals>b__6` I just cannot grok.
What's more, this expression cannot be compiled with C# compiler, so I need to come up with something more friendly. Tried to google parts of this, but with no luck. Could you give me some hints? It seems it can have something to do with anonymous methods, but that's my best guess.

Thanks in advance.