IOUtil.assertFileIsReadable(INPUT);
IOUtil.assertFileIsWritable(OUTPUT);
final VCFFileReader reader = new VCFFileReader(INPUT, REQUIRE_INDEX);
final VCFHeader header = new VCFHeader(reader.getFileHeader());
final SAMSequenceDictionary sequenceDictionary = header.getSequenceDictionary();
if (CREATE_INDEX && sequenceDictionary == null) {
throw new PicardException("A sequence dictionary must be available in the input file when creating indexed output.");
}
final VariantContextWriterBuilder builder = new VariantContextWriterBuilder()