code: @Override
      public void visit(final Source source) {
          titleString = source.getString();
          for (final GedObject gob : source.getAttributes()) {
              gob.accept(this);
          }
      }
docs: Visit a Source. This is the primary focus of the visitation. From
  here, interesting information is gathered.
  
  @see GedObjectVisitor#visit(Source)