[
  {
    "name": "id",
    "type": "INTEGER",
    "mode": "REQUIRED"
  },
  {
    "name": "string_field",
    "type": "STRING",
    "mode": "NULLABLE"
  },
  {
    "name": "timestamp_field",
    "type": "TIMESTAMP",
    "mode": "NULLABLE"
  },
  {
    "name": "date",
    "type": "DATE",
    "mode": "REQUIRED"
  }
]