transpose
Function
transpose
takes a map of lists of strings and swaps the keys and values
to produce a new map of lists of strings.
Examples
> transpose({"a" = ["1", "2"], "b" = ["2", "3"]})
{
"1" = [
"a",
],
"2" = [
"a",
"b",
],
"3" = [
"b",
],
}