public Boolean isNullable(M member) {
        Set<Boolean> result = this.nullableChecks.stream()
                .map(check -> check.apply(member))
                .filter(Objects::nonNull)
                .collect(Collectors.toSet());
        return result.isEmpty() ? null : result.stream().anyMatch(value -> value);
    }
Determine whether a given member is nullable.

@param member member to check
@return whether the member is nullable (may be null if not specified)
jsonschema-generator/src/main/java/com/github/victools/jsonschema/generator/SchemaGeneratorConfigPart.java