encodeTopics = ({ topic, partitionAssignment }) => {
  return new Encoder()
    .writeUVarIntString(topic)
    .writeUVarIntArray(partitionAssignment.map(encodePartitionAssignment))
    .writeUVarIntBytes()
}
AlterPartitionReassignments Request (Version: 0) => timeout_ms [topics] TAG_BUFFER
timeout_ms => INT32
topics => name [partitions] TAG_BUFFER
 name => COMPACT_STRING
 partitions => partition_index [replicas] TAG_BUFFER
   partition_index => INT32
   replicas => INT32