For example, I want to generate:
{'type!{myNamespace}MY_Cdt'(first: 1, second: "A"),
'type!{myNamespace}MY_Cdt'(first: 2, second: "B"),
'type!{myNamespace}MY_Cdt'(first: 3, second: "C")}

From these arrays:
firstArray: {1,2,3}
secondArray: {"A","B","C"}

I've tried the following syntax, but it just stores the arrays in a scalar CDT:
'type!{myNamespace}MY_Cdt'(first: firstArray, second: secondArray)