This PR [containerDefaultToNull ](https://github.com/Backbase/backbase-openapi-tools/pull/593) has changed default behaviour. Generated code is invalid. ```java @Valid private List<@Valid PaymentRequestLine> lines; ... @NotNull @Valid @Schema(name = "lines", requiredMode = Schema.RequiredMode.REQUIRED) @JsonProperty("lines") public List<@Valid PaymentRequestLine> getLines() { return lines; } ``` By default there should be empty collection generated (with posibility to override it).