rules:
  - id: maybe-wrong-err
    patterns:
        - pattern-either:
              - pattern: |
                      if $F.Err() != nil {
                              return ..., <... err ...>
                      }
              - pattern: |
                      if $F.Err() != nil {
                              return <... err ...>
                      }

    message: "maybe returning wrong error"
    languages: [go]
    severity: ERROR