def __init__(self, generator, iterate_once=False, exc_handler=None):
        """If `iterate_once` is `True`, the generator is iterated once (by
        calling `next()`) immediately after construction, in order to be able
        to pass the parameters of the first `__call__()` to the generator by
        calling `send()`. Any yielded value is discarded. Note that if the
        first `__call__()` passes no arguments or a single `None`, the first
        iteration will succeed, and the generator need not be iterated once to
        initialize it.

        Note also that the default exception handler for a wrapper is `None`,
        so that exceptions are raised to the caller of `__call__()`.
        """
        Executor.__init__(self, generator, exc_handler)
        if iterate_once: generator.next()
If `iterate_once` is `True`, the generator is iterated once (by
        calling `next()`) immediately after construction, in order to be able
        to pass the parameters of the first `__call__()` to the generator by
        calling `send()`. Any yielded value is discarded. Note that if the
        first `__call__()` passes no arguments or a single `None`, the first
        iteration will succeed, and the generator need not be iterated once to
        initialize it.

        Note also that the default exception handler for a wrapper is `None`,
        so that exceptions are raised to the caller of `__call__()`.
        
recipes/Python/576965_Multicontext_eg_asynchronous_inline/recipe-576965.py