code: @Override
      public org.fcrepo.server.types.gen.Datastream getDatastream(String pid,
                                                                  String dsID,
                                                                  String asOfDateTime) {
          assertInitialized();
          try {
              MessageContext ctx = context.getMessageContext();
              org.fcrepo.server.storage.types.Datastream ds =
                      m_management.getDatastream(ReadOnlyContext
                              .getSoapContext(ctx), pid, dsID, DateUtility
                              .parseDateOrNull(asOfDateTime));
              return TypeUtility.convertDatastreamToGenDatastream(ds);
          } catch (Throwable th) {
              LOG.error("Error getting datastream", th);
              throw CXFUtility.getFault(th);
          }
      }
docs: /*
  (non-Javadoc)
  @see org.fcrepo.server.management.FedoraAPIMMTOM#getDatastream( String
  pid ,)String dsID ,)String asOfDateTime )*