Many of the stories have an implicit actor or user of a developer using an API, so read "As a developer, I wish to use the [Java|C#] library to ...."
RFC5322 and MIME Component Stories
See  for an exhaustive list of behavior driven development testable specs against the Ruby mail library.
DNS CERT Resolver Stories
The following stories assume a general DNS resolver library that can retrieve DNS RRs. Note that these stories do not add up to a general purpose CERT resolver; they only support features explicitly required in the specification
- Parse a CERT RR, extracting the component fields.
- Extract a Certificate object from a CERT RR (Base 64 decode the field and read the DER representation)
- Perform a TCP-based DNS query (note that DNS often uses UDP)
- Resolve a CERT record by email address (single valid X509 CERT record exists for the email address)
- Resolve a CERT record by email address (single valid X509 CERT record exists for the wildcard for the address)
- Resolve a CERT record by email address (multiple valid X509 CERT records exist for the email address)
- Resolve a CERT record by email address (multiple X509 and non X509 CERT records exist for the email address)
- Resolve a CERT record, error conditions (timeout, incomplete or incorrect information returned, invalid certificate record)
- Basic metadata objects, with properties and sub-objects covering the core XD* metadata elements
- Per element, serialize as ebXML
- Per element, unserialize as ebXML
See IHE documentation and Keith's blog posting for details
Suggest "storyizing" and unit testing on a per property basis, starting with the XDS required properties.
Message Object with Document Set
Encapsulation of a message, with sender, receivers, documents, metadata
- Basic message, object, with sender, receivers, contained metadata object
- Support adding, reading documents and associated metadata
- Serialize/deserialize as pure RFC5322 (email message with multipart/mixed and Base64 encoded attachments
- Serialize/deserialize as XDM zip file (autocreate HTML file)
- Serialize/deserialize as RFC5322 with XDM attachment