const TransferSchema = new Schema({
  token: {
    type: ByteArray,
    length: 4,
    required: true
  },
  start: {
    type: ByteArray,
    length: 12,
    required: true
  },
  end: {
    type: ByteArray,
    length: 12,
    required: true
  },
  sender: {
    type: Address,
    required: true
  },
  recipient: {
    type: Address,
    required: true
  }
})