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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 has_all_changes_covered(self):
 """ Return `True` if all changes have been covered, `False` otherwise. """

        for filename in self.files():
            for hunk in self.file_source_hunks(filename):
                for line in hunk:
                    if line.reason is None:
                        continue  # line untouched
                    if line.status is False:
                        return False  # line not covered
        return True