/// <summary>
/// Registers extension method as instance method which will be included into strongly typed
/// reflection lookup performed by <see cref="Type{T}.Method.Get{D}(string, MethodLookup, bool)"/> and related methods.
/// </summary>
/// <param name="method">Static method to register. Cannot be <see langword="null"/>.</param>
public static void RegisterInstance(MethodInfo method)
{
var thisParam = method.GetParameterTypes().FirstOrDefault();
if (!method.IsStatic || thisParam is null)
{
throw new ArgumentException(ExceptionMessages.ExtensionMethodExpected(method), nameof(method));
}
if (thisParam.IsByRef)
{
thisParam = thisParam.GetElementType();
}
GetOrCreateRegistry(thisParam, MethodLookup.Instance).Add(method);
}
