code: public void taintPackage(String name, String because) {
          if (!taintedPackages.contains(name)) {
              if (because != null) Log.debug("Tainting "+Util.justPackageName(name)+" because "+because);
              // It has not been tainted before.
              taintedPackages.add(name);
              needsSaving();
              Package nowp = now.packages().get(name);
              if (nowp != null) {
                  for (String d : nowp.dependents()) {
                      taintPackage(d, because);
                  }
              }
          }
      }
docs: Mark a java package as tainted, ie it needs recompilation.