code: public static SAMFileHeader readSAMHeaderFrom(
  		final InputStream in, final Configuration conf)
  	{
  		final ValidationStringency
  			stringency = getValidationStringency(conf);
  		SamReaderFactory readerFactory = SamReaderFactory.makeDefault()
  				.setOption(SamReaderFactory.Option.EAGERLY_DECODE, false)
  				.setUseAsyncIo(false);
  		if (stringency != null) {
  			readerFactory.validationStringency(stringency);
  		}
  
  		final ReferenceSource refSource = getReferenceSource(conf);
  		if (null != refSource) {
  			readerFactory.referenceSource(refSource);
  		}
  		return readerFactory.open(SamInputResource.of(in)).getFileHeader();
  	}
docs: Does not close the stream.