FeatureFileFormat featureFileFormat = DocumentUtils.guessFeaturesFileFormat(featureFile);
if (featureFileFormat == FeatureFileFormat.UNKNOWN) {
throw new RuntimeIOException("Unknown feature file format. Please provide file in GFF/GTF or BED format.");
}
if (featureFileFormat == FeatureFileFormat.GTF) {
// while not interested in GTF-specific information we save some memory by using GFF reader
featureFileFormat = FeatureFileFormat.GFF;