@Override
    public void checkInitialization(InitializableProblemHandler problemHandler)
            throws TikaConfigException {
        if (supportedTypes.size() == 0) {
            throw new TikaConfigException("supportedTypes size must be > 0");
        }
        if (commandLine.isEmpty()) {
            throw new TikaConfigException("commandLine is empty?!");
        }

        if (outputParser == EmptyParser.INSTANCE) {
            LOG.debug("no parser selected for the output; contents will be " +
                    "written to the content handler");
        }
    }
This parser is called on the output of the process.
If the process writes to an output file, specified by
{@link ExternalParser#OUTPUT_FILE_TOKEN}, this parser will parse that file,
otherwise it will parse the UTF-8 encoded bytes from the process' STD_OUT.
@param parser
tika-core/src/main/java/org/apache/tika/parser/external2/ExternalParser.java