THPDFJSONValue.GetArr
Returns the array member stored under a key, or nil when the member is absent or is not an array
function GetArr(const Key: AnsiString): THPDFJSONValue;
The unit is HPDFDocJobs; the returned array belongs to this object and must not be freed by the caller
Iterate the result with ItemCount and Item
NewArrayMember creates and attaches a new array member