Version v3.6.6 available.

[janiversen]

Version v3.6.5 have a problem for async app in close() that may cause an exception.

Version v3.6.6 solves that problem, and furthermore adds more type checking and a lot more test cases.

Sorry for the inconvenience, but we found it better to make a fast bug fix release, than to wait.

Version v3.6.7 or v3.7.0 are not to be expected for the next 1-2 months.