public InputStream getInputStream(final String streamTypeName, final Path file) throws IOException {
        if (streamTypeName == null) {
            throw new IllegalArgumentException("Must Have a non-null stream type");
        }
        if (FileStoreType.bgz.equals(getFileStoreType(streamTypeName))) {
            return new BlockGZIPInputFile(file);
        }
        return new UncompressedInputStream(file, isStreamTypeLazy(streamTypeName));
    }
Return back a input stream for a given stream type and file.
stroom-data/stroom-data-store-impl-fs/src/main/java/stroom/data/store/impl/fs/FsPathHelper.java