docs: def mksalt(method=None, rounds=None):
      """Generate a salt for the specified method.
      If not specified, the strongest available method will be used.
      """
      if method is None:
          method = methods[0]
      salt = ['${0}$'.format(method.ident) if method.ident else '']
      if rounds:
          salt.append('rounds={0:d}$'.format(rounds))
      salt.append(''.join(_sr.choice(_BASE64_CHARACTERS) for char in range(method.salt_chars)))
      return ''.join(salt)