'Update table of contents mapping.'

def _refresh(self):

    self._toc = {}
    for path in self._paths:
        for (dirpath, dirnames, filenames) in os.walk(self._paths[path]):
            for filename in [f for f in filenames if (f.endswith('.eml.gz') or f.endswith('.eml'))]:
                self._toc[filename] = os.path.join(dirpath, filename)
