How to enclose null/Empty, single or multiple objects in array

Question

I have an external API that sends data in any of 2 possible ways, like a single object or an array of objects. In both cases, I would expect to get the result in an array format.

1.
{

  "PONumber": "1000445525",
  "POLineItem": "10",
  "NeedInDCDate": "10/08/2022",
  "SourceSystem": "o9LCT",
  "Region": "LSA"
} 

2.
[
{
  "PONumber": "1000445525",
  "POLineItem": "10",
  "NeedInDCDate": "10/08/2022",
  "SourceSystem": "o9LCT",
  "Region": "LSA"
},
{  "PONumber": "1000474525",
  "POLineItem": "10",
  "NeedInDCDate": "10/08/2022",
  "SourceSystem": "o9LCT",
  "Region": "LSE"
}
]

Excepted output

1. 
[
{
  "PONumber": "1000445525",
  "POLineItem": "10",
  "NeedInDCDate": "10/08/2022",
  "SourceSystem": "o9LCT",
  "Region": "LSA"
}
]

2. 
[
{
  "PONumber": "1000445525",
  "POLineItem": "10",
  "NeedInDCDate": "10/08/2022",
  "SourceSystem": "o9LCT",
  "Region": "LSA"
},
{  "PONumber": "1000474525",
  "POLineItem": "10",
  "NeedInDCDate": "10/08/2022",
  "SourceSystem": "o9LCT",
  "Region": "LSE"

]

Please help with jolt spec