Get all instances of custom attribute defined only for classes with allowmultiple=false , useful when using FluentMigrator

AssemblyExtensions.cs

public static class AssemblyExtensions{
public static List<TCustomAttribute> GetAllCustomAttributeInstances<TCustomAttribute>(this Assembly assembly)
            where TCustomAttribute : Attribute
        {
            var supportedMigrationVersions = assembly
                .GetTypes()
                .Where(t => Attribute.IsDefined(t, typeof(TCustomAttribute)))
                .Select(t => (t.GetCustomAttribute(typeof(TCustomAttribute)) as TCustomAttribute))
                .ToList();

            return supportedMigrationVersions;
        }
}