Microsoft-CISL/TANG — pull request #191 by yingdachen (2014-08-29 16:31:48+00:00)
Title: add helper method to see if optional parameter/implmentation is bound

Sometimes it is helpful to be able to tell whether an optional parameter or implementation is bound in a configuration or not (for example, if one want to provide a non-constant default value at runtime if the value is not bound). Currently it is pretty awkward to find that out. This pull request add a helper method to do it.