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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 _normalize_compare_config(self, diff):
 """Filter out strings that should not show up in the diff."""

        ignore_strings = [
            "Contextual Config Diffs",
            "No changes were found",
            "ntp clock-period",
        ]
        if self.auto_file_prompt:
            ignore_strings.append("file prompt quiet")

        new_list = []
        for line in diff.splitlines():
            for ignore in ignore_strings:
                if ignore in line:
                    break
            else:  # nobreak
                new_list.append(line)
        return "\n".join(new_list)