InputSynapse.cs

 public class InputSynapse : ISynapse
{
    internal INeuron _toNeuron;

    public double Weight { get; set; }
    public double Output { get; set; }
    public double PreviousWeight { get; set; }

    public InputSynapse(INeuron toNeuron)
    {
        _toNeuron = toNeuron;
        Weight = 1;
    }

    public InputSynapse(INeuron toNeuron, double output)
    {
        _toNeuron = toNeuron;
        Output = output;
        Weight = 1;
        PreviousWeight = 1;
    }

    public double GetOutput()
    {
        return Output;
    }

    public bool IsFromNeuron(Guid fromNeuronId)
    {
        return false;
    }

    public void UpdateWeight(double learningRate, double delta)
    {
        throw new InvalidOperationException("It is not allowed to call this method on Input Connecion");
    }
}