Here is publisher

using System;
…
public event EventHandler RailsEnabled;

void EnableRails()
{
if (RailsEnabled != null)
RailsEnabled(this, EventArgs.Empty);
}

Here is subscriber

void Start () {
Launcher.RailsEnabled += OnRailsEnabled;
}

private void OnRailsEnabled(object sender, EventArgs e)
{
RailsEnabled = true;
}

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