def _step00(self, in_row, tmp_row, out_row):
for key, value in in_row.items():<EOL><INDENT>in_row[key] = WhitespaceCleaner.clean(value)<EOL><DEDENT>return None, None<EOL>
Prunes whitespace for all fields in the input row.

:param dict in_row: The input row.
:param dict tmp_row: Not used.
:param dict out_row: Not used.