struct BaseWireResultStorage

|BaseWireResultStorage| is a set of templates which define how the |Unwrap| method in

|BaseWireResult| will access the decoded value from a two-way method call.

This is only needed for two-way methods which have a non-empty payload or an

domain error. For one-way methods and two-way methods with an empty

payload and no use of error syntax, |BaseWireResult| doesn't store anything.