.filter(s -> !requiredValidator.isValid(source.get(s), null)).collect(Collectors.toList()));
    }

    default boolean isNonEmptyValue(final Object value) {
        final RequiredValidator requiredValidator = new RequiredValidator();
        return requiredValidator.isValid(value, null);
    }

    String getCrawlerDocumentSpaceChars();

        }

        if ( log.isDebugEnabled() ) {
            log.debug("Negotiation response on " + this.name + " :" + resp);
        }

        if ( !resp.getResponse().isValid(getContext(), resp.getRequest()) ) {
            throw new SmbException("This client is not compatible with the server.");
        }

        boolean serverRequireSig = resp.getResponse().isSigningRequired();