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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 long_description(*filenames):
 """Provide a long description."""

    res = ['']
    for filename in filenames:
        with open(filename) as fp:
            for line in fp:
                res.append('   ' + line)
            res.append('')
        res.append('\n')
    return EMPTYSTRING.join(res)