@extensionmethod(Observable)
def __iadd__(self, other):

    return self.concat(self, other)
Test the seek functionality.
dataset/ETHPy150Open ReactiveX/RxPY/rx/linq/observable/concat.py/__iadd__--crossover with--dataset/ETHPy150Open log2timeline/dfvfs/tests/file_io/encrypted_stream_io.py/AESEncryptedStreamTest.testSeek