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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 isoformat(dt):
 """Return an ISO-8601 formatted string from the provided datetime object"""

    if not isinstance(dt, datetime.datetime):
        raise TypeError("Must provide datetime.datetime object to isoformat")

    if dt.tzinfo is None:
        raise ValueError("naive datetime objects are not allowed beyond the library boundaries")

    return dt.isoformat().replace("+00:00", "Z")