%dw 2.0

fun a(a: Number) = a

fun a(a: Number, b: Number) = a ++ b

fun b(a: Any) = a

fun b(a: String, b) = a ++ b

fun c(a: String, b: Number, d: String = "test") = a ++ b ++ d

output application/dw
---
{
    a: map([1], a),
    b: map(["2"], b),
    c: map(["2"], c)
}