public static TSource SingleOrFallback<TSource>(
	this IEnumerable<TSource> source,
	Func<TSource> fallback
)

<ExtensionAttribute> _
Public Shared Function SingleOrFallback(Of TSource) ( _
	source As IEnumerable(Of TSource), _
	fallback As Func(Of TSource) _
) As TSource

public:
[ExtensionAttribute]
generic<typename TSource>
static TSource SingleOrFallback(
	IEnumerable<TSource>^ source, 
	Func<TSource>^ fallback
)