title: Delay property on Binding from .Net 4.5 in .Net 4.0
body: <p>How can I implement Delay property from .Net 4.5 (described <a href="http://msdn.microsoft.com/en-us/library/system.windows.data.bindingbase.delay%28v=vs.110%29.aspx" rel="noreferrer">here</a>) on binding in .Net 4.0?</p>
  
  <p>I know I cannot inherit from BindingBase as ProvideValue is sealed. </p>
  
  <p>I could implement MarkupExtension but it means I now have to rewrite all properties from BindingExtension is there any other way?</p>