code: List<Snippet> sourceToSnippetsWithWrappers(String userSource) {
          List<Snippet> snippets = sourceToSnippets(userSource);
          for (Snippet snip : snippets) {
              if (snip.outerWrap() == null) {
                  snip.setOuterWrap(
                          (snip.kind() == Kind.IMPORT)
                                  ? state.outerMap.wrapImport(snip.guts(), snip)
                                  : state.outerMap.wrapInTrialClass(snip.guts())
                  );
              }
          }
          return snippets;
      }
docs: Converts the user source of a snippet into a Snippet list -- Snippet will
  have wrappers.
  
  @param userSource the source of the snippet
  @return usually a singleton list of Snippet, but may be empty or multiple