protected List<String> resolveEnum(MemberScope<?, ?> member) {
        return this.getSchemaAnnotationValue(member, Schema::allowableValues, values -> values.length > 0)
                .map(Arrays::asList)
                .orElse(null);
    }
Look-up the finite list of possible values from {@code @Schema(allowableValues = ...)}.

@param member field/method to determine allowed values for
@return applicable "const"/"enum" values or null
jsonschema-module-swagger-2/src/main/java/com/github/victools/jsonschema/module/swagger2/Swagger2Module.java