[
   {
       "id": "1",
       "fieldValue": "test title"
   },
   {
       "id": "2",
       "fieldValue": [
          "option 1",
          "option 3",
          "option 4"
      ]
   },
   {
       "id": "3",
       "fieldValue": 9999,
       "fieldCurrency": "cad"
   },
   {
       "id": "4",
       "fieldValue": "100.99"
   },
   {
       "id": "5",
       "fieldValue": "2018-12-31"
   },
   {
       "id": "6",
       "fieldValue": "2020-05-19T02:45:00-05:00" //ISO format
   }
]

{
    "message": "AccountCustomFieldDatas with ID(s): 1, 2, 3, 4, 5 successfully bulk updated."
}