@tbekolay @drasmuss misunderstanding... I was suggesting that time *always* be an input, the first input. Specifying an `in_dimensions` argument would indicate that the node should also have an input that can be connected to, and that will be passed to the Python function. (Also, in case it's important-- I wasn't talking about sinks at all.)

```python
Node(np.sin)  # works as now
Node(np.sin, in_dimensions=1) # model builds, fails at runtime because sin takes only 1 arg
Node(np.sin, out_dimensions=1) # avoids initial call to determine output dimensionality
Node(specific_logger) # fails at build time because Node would try to call it with one arg to determine output dims
Node(specific_logger, out_dimensions=None) # fails at runtime because node would call it with one arg (time)
Node(specific_logger, in_dimensions=101, out_dimensions=None) # works if you connect it up right.
```