In case you all are wondering how to call custom node from a code block in Dynamo, here is the solution.
When you drop a custom node in Dynamo canvas and if any of the input is missing then it's output is a Function object. A function object can be executed using the method DoEvaluation as shown below.
What if you want to pass multiple input to your custom node from the code block, then you need to chain the call of node.DoEvaluation(x).DoEvaluation(y) as follows:
You can also call your custom node inside the imperative block.
Please note that DoEvaluation method on function object is an internal method and may change in future.