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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 from_file(cls, filename):
 """ Read an Fiesta input from a file. Currently tested to work with files generated from this class itself. Args: filename: Filename to parse. Returns: FiestaInput object """

        with zopen(filename) as f:
            return cls.from_string(f.read())