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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 _find_config(self):
 """Searches through the configured `config_paths` for the `config_name` file. If there are no `config_paths` defined, this will raise an error, so the caller should take care to check the value of `config_paths` first. Returns: str: The fully qualified path to the configuration that was found. Raises: Exception: No paths are defined in `config_paths` or no file with the `config_name` was found in any of the specified `config_paths`. """

        for search_path in self.config_paths:
            for ext in self._fmt_to_ext.get(self.config_format):
                path = os.path.abspath(os.path.join(search_path, self.config_name + ext))
                if os.path.isfile(path):
                    self.config_file = path
                    return
        raise BisonError('No file named {} found in search paths {}'.format(
            self.config_name, self.config_paths))