Kafka records may be a table, overriding the following: 
{
  topic = 'override', -- will use this over the mirror's destination table
  key = 'partition key',
  value = 'record value',
  partition = 91, -- for use with Manual partitioner
  headers = {
    header1 = 'value1',
    header2 = 'value2',
  },
}