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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 assert_is_not_none(expr, msg_fmt="{msg}"):
 """Fail if the expression is None. Traceback (most recent call last):
 AssertionError: expression is None The following msg_fmt arguments are supported: * msg - the default error message * expr - tested expression """

    if expr is None:
        msg = "expression is None"
        fail(msg_fmt.format(msg=msg, expr=expr))