Turn a Topic string into an LBMTopic object usable by receivers.
It is recommended that topic objects be instantiated from the context
factory methods allocTopic()
and lookupTopic() (for
sources and receivers respectively).

C# |
public LBMTopic( LBMContext lbmctx, string symbol )

- lbmctx (LBMContext)
- LBMContext object for the topic
- symbol (String)
- Topic string (Topic strings should be limited in length to 246 characters, not including the final null).

Note: This constructor cannot be used to initialize a source topic.
Warning: It is not safe to call this constructor from a context thread callback.
