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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 read_relative_file(filename, relative_to=None):
 """Returns contents of the given file, which path is supposed relative to this package."""

    if relative_to is None:
        relative_to = os.path.dirname(__file__)
    with open(os.path.join(os.path.dirname(relative_to), filename)) as f:
        return f.read()