Constructor.
Stream or how to open the stream.
stream
could be:
DataTape.Reader methods are available only if the stream is readable. DataTape.Writer methods are available only if the stream is writable.
If stream
is a stream instance, it allows either one read or multiple writes.
If stream
is an opener function or filename, it allows multiple reads and writes.
Function calls must be sequenced because this type is non-thread-safe.
DataTape is a file or stream that consists of a sequence of Data packets. This type implements DataStore interfaces on top of such a file or stream.