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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 header(msg):
 """ Wrap `msg` in bars to create a header effect """

    # Accounting for '| ' and ' |'
    width = len(msg) + 4
    s = []
    s.append('-' * width)
    s.append("| %s |" % msg)
    s.append('-' * width)
    return '\n'.join(s)