code: public TypeElement findClassInPackageElement(PackageElement pkg, String className) {
          for (TypeElement c : getAllClasses(pkg)) {
              if (getSimpleName(c).equals(className)) {
                  return c;
              }
          }
          return null;
      }
docs: Lookup for a class within this package.
  
  @return TypeElement of found class, or null if not found.