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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def to_bytes(s):
 # pragma: nocover """Convert an item into bytes. """

    if isinstance(s, bytes):
        return s
    if isinstance(s, str) or is_unicode(s):
        return s.encode("utf-8")
    try:
        return unicode(s).encode("utf-8")
    except NameError:
        return str(s).encode("utf-8")