<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def escape_string(self, string):
 """Return the escaped literal representation of an nbt string."""

        if self.quote:
            quote = self.quote
        else:
            found = QUOTE_REGEX.search(string)
            quote = STRING_QUOTES[found.group()] if found else next(iter(STRING_QUOTES))

        for match, seq in ESCAPE_SUBS.items():
            if match == quote or match not in STRING_QUOTES:
                string = string.replace(match, seq)

        return f'{quote}{string}{quote}'