public static TDynamic If<TDynamic>(
	this TDynamic container,
	string expression,
	Object thenContent,
	Object elseContent = null
)
where TDynamic : DynamicJson

public static TDynamic If<TDynamic>(
	this TDynamic container,
	string expression,
	Object thenContent,
	Object elseContent = null
)
where TDynamic : DynamicJson

<ExtensionAttribute> 
Public Shared Function If(Of TDynamic As DynamicJson) ( 
	container As TDynamic,
	expression As String,
	thenContent As Object,
	Optional elseContent As Object = Nothing
) As TDynamic

<ExtensionAttribute> 
Public Shared Function If(Of TDynamic As DynamicJson) ( 
	container As TDynamic,
	expression As String,
	thenContent As Object,
	Optional elseContent As Object = Nothing
) As TDynamic