code: public static Vector<Qualifier> getFeatureQualifiers(Entry entry, Feature feature) {
      	Vector<Qualifier> qualifiers = new Vector<Qualifier>();
          if (feature instanceof SourceFeature) {
          	String scientificName = ((SourceFeature)feature).getScientificName();
          	if (!FlatFileUtils.isBlankString(scientificName)) {
          		Qualifier qualifier = (new QualifierFactory()).
          			createQualifier("organism", scientificName);
          		qualifiers.add(qualifier);
          	}
          	String moleculeType = entry.getSequence().getMoleculeType(); 
          	if(!FlatFileUtils.isBlankString(moleculeType)) {
          		Qualifier qualifier = (new QualifierFactory()).
      			createQualifier("mol_type", moleculeType);
          		qualifiers.add(qualifier);
          	}
          	Long taxId = ((SourceFeature)feature).getTaxId();
          	if (taxId != null && taxId > -1 /* do not show negative taxIds */ ) {
          		Qualifier qualifier = (new QualifierFactory()).
          			createQualifier("db_xref", "taxon:" + taxId.toString());
          		qualifiers.add(qualifier);        		
          	}
          }
      	for (Qualifier qualifier : feature.getQualifiers()) {	    	
      		String name = qualifier.getName();
      		String value = qualifier.getValue();
      		if (name == null) {
      			continue;
      		}
      		if (name.equals(Qualifier.ORGANISM_QUALIFIER_NAME)) {
      			continue; // Ignore /organism qualifiers.
      		}
      		if (name.equals(Qualifier.MOL_TYPE_QUALIFIER_NAME)) {
      			continue; // Ignore /mol_type qualifiers.
      		}
      		if (name.equals(Qualifier.DB_XREF_QUALIFIER_NAME) &&
  				value != null && value.startsWith("taxon:")) {
      			continue; // Ignore /db_xref="taxon:" qualifiers.
      		}
      		qualifiers.add(qualifier);
      	}
      	return qualifiers;    	
      }
docs: Adds organism, /mol_type and /db_ref="taxon:" feature qualifiers into
  the source feature. If these qualifiers already exist they are removed.