- """Check if :class:`Threads` contains at least one more valid thread
-
- The existence of this function makes 'if Threads: foo' work, as
- that will implicitely call len() exhausting the iterator if
- __nonzero__ does not exist. This function makes `bool(Threads())`
- work repeatedly.
+ '''
+ Implement truth value testing. If __nonzero__ is not
+ implemented, the python runtime would fall back to `len(..) >
+ 0` thus exhausting the iterator.