protected Boolean isNullable(MemberScope<?, ?> member) {
        Boolean result;
        if (member.isFakeContainerItemScope()) {
            // annotations on the field/method are assumed to refer to the surrounding container
            result = null;
        } else if (this.getAnnotationFromFieldOrGetter(member, NotNull.class, NotNull::groups) != null
                || this.getAnnotationFromFieldOrGetter(member, NotBlank.class, NotBlank::groups) != null
                || this.getAnnotationFromFieldOrGetter(member, NotEmpty.class, NotEmpty::groups) != null) {
            // field is specifically NOT nullable
            result = Boolean.FALSE;
        } else if (this.getAnnotationFromFieldOrGetter(member, Null.class, Null::groups) != null) {
            // field is specifically null (and thereby nullable)
            result = Boolean.TRUE;
        } else {
            result = null;
        }
        return result;
    }
Determine whether a given field or method is annotated to be not nullable.

@param member the field or method to check
@return whether member is annotated as nullable or not (returns null if not specified: assumption it is nullable then)
jsonschema-module-jakarta-validation/src/main/java/com/github/victools/jsonschema/module/jakarta/validation/JakartaValidationModule.java