docs: def _get_ssl_opts():
      '''
      Parse out ssl_options for Cassandra cluster connection.
      Make sure that the ssl_version (if any specified) is valid.
      '''
      sslopts = __salt__['config.option']('cassandra').get('ssl_options', None)
      ssl_opts = {}
  
      if sslopts:
          ssl_opts['ca_certs'] = sslopts['ca_certs']
          if SSL_VERSION in sslopts:
              if not sslopts[SSL_VERSION].startswith('PROTOCOL_'):
                  valid_opts = ', '.join(
                      [x for x in dir(ssl) if x.startswith('PROTOCOL_')]
                  )
                  raise CommandExecutionError('Invalid protocol_version '
                                              'specified! '
                                              'Please make sure '
                                              'that the ssl protocol'
                                              'version is one from the SSL'
                                              'module. '
                                              'Valid options are '
                                              '{0}'.format(valid_opts))
              else:
                  ssl_opts[SSL_VERSION] = \
                      getattr(ssl, sslopts[SSL_VERSION])
          return ssl_opts
      else:
          return None