#vulnerable code 
                              protected Map<String, Object> customSettingsFlat() {
    return ImmutableMap.<String, Object>builder()
        .put(HTTP_INCOMING_AUTH_TYPE, IlpOverHttpLinkSettings.AuthType.JWT_HS_256.name())
        .put(HTTP_INCOMING_TOKEN_ISSUER, "https://incoming-issuer.example.com/")
        .put(HTTP_INCOMING_SHARED_SECRET, "incoming-credential")
        .put(HTTP_INCOMING_TOKEN_AUDIENCE, "https://incoming-audience.example.com/")

        .put(HTTP_OUTGOING_AUTH_TYPE, IlpOverHttpLinkSettings.AuthType.SIMPLE.name())
        .put(HTTP_OUTGOING_TOKEN_SUBJECT, "outgoing-subject")
        .put(HTTP_OUTGOING_SHARED_SECRET, "outgoing-credential")
        .put(HTTP_OUTGOING_TOKEN_ISSUER, "https://outgoing-issuer.example.com/")
        .put(HTTP_OUTGOING_TOKEN_AUDIENCE, "https://outgoing-audience.example.com/")
        .put(HTTP_OUTGOING_TOKEN_EXPIRY, Duration.ofDays(1).toString())
        .put(HTTP_OUTGOING_URL, "https://outgoing.example.com")

        .build();
  } 
                            #location 1 
                            #vulnerability type CHECKERS_IMMUTABLE_CAST
#fixed code
                              protected Map<String, Object> customSettingsFlat() {
    return customSettingsFlat(IlpOverHttpLinkSettings.AuthType.JWT_HS_256, IlpOverHttpLinkSettings.AuthType.JWT_HS_256);
  }