Consider multi-threading for default writer
Currently multi threading is not considered. This means if the same id is used from multiple threads, it could be possible that spans / trace points are mixed and analysis is no longer possible.
These are the items we need to solve this issue:
* An example or test that demonstrate if there is an issue
* A concept how to solve this issue
* An implementation of this issue as well as fixing / modification of the tests or examples created for this issue
issue