Use this rule to prevent multiple entries with the same key in mappings.

Examples

When enabled the following code snippet would PASS:

    - key 1: v
      key 2: val
      key 3: value
    - {a: 1, b: 2, c: 3}

the following code snippets would FAIL:

    - key 1: v
      key 2: val
      key 1: value

the following code snippet would FAIL:

- {a: 1, b: 2, b: 3}

the following code snippets would FAIL:

    duplicated key: 1
    "duplicated key": 2

    other duplication: 1
    ? >-
        other
        duplication
    : 2