code: Symbol findImmediateMemberType(Env<AttrContext> env,
                                     Type site,
                                     Name name,
                                     TypeSymbol c) {
          for (Symbol sym : c.members().getSymbolsByName(name)) {
              if (sym.kind == TYP) {
                  return isAccessible(env, site, sym)
                      ? sym
                      : new AccessError(env, site, sym);
              }
          }
          return typeNotFound;
      }
docs: Find a type declared in a scope (not inherited).  Return null
  if none is found.
  @param env       The current environment.
  @param site      The original type from where the selection takes
  place.
  @param name      The type's name.
  @param c         The class to search for the member type. This is
  always a superclass or implemented interface of
  site's class.