Well then why don’t you move those two lines from Tobii.StreamEngine.Interop.cs to Tobii.StreamEnginePartner.Interop.cs:
[DllImport(stream_engine_dll, CallingConvention = CallingConvention.Cdecl, EntryPoint = “tobii_calibration_stimulus_points_get”)]
private static extern tobii_error_t tobii_calibration_stimulus_points_get(IntPtr device, out tobii_calibration_stimulus_points_t stimulus_points);
This function is never called in the C# binding, and according to what you said, will never be used by clients without an NDA including me. It does nothing except generating an error. I think it doesn’t belong here.