def f_reversible_inverse(self, program):
    """Adds 'alias' back to the names of tables."""
    table_name_regex = r" [^ ]+? as ([^ ]+?) "
    table_names = re.findall(table_name_regex, program)
    program_processed = str(program)
    for table_name in table_names:
      # Insert 'alias' before the numerical suffix.
      table_name_original = re.sub(r"(.+)(\d+)", r"\1alias\2", table_name)
      program_processed = program_processed.replace(table_name,
                                                    table_name_original)
    return program_processed
Adds 'alias' back to the names of tables.
language/compir/dataset_parsers/sql_parser.py