---
cases:
  - data: {}
    modules:
      - |
        package generated

        p = x {
          s1 = {"a", "b", "c", "d"}
          s2 = {"b", "c", "d"}
          s3 = {"c", "d"}
          s4 = {"d"}
          union({s1, s2, s3, s4}, x)
        }
    note: union/union_4_sets
    query: data.generated.p = x
    sort_bindings: true
    want_result:
      - x:
          - a
          - b
          - c
          - d
