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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 files(self, absolute=False):
 """Returns an expanded list of all valid paths that were passed in."""


        _paths = []

        for arg in self.all:
            for path in _expand_path(arg):
                if os.path.exists(path):
                    if absolute:
                        _paths.append(os.path.abspath(path))
                    else:
                        _paths.append(path)

        return _paths