code: private Scope membersOf(ClassSymbol c) {
          try {
              return c.members();
          } catch (CompletionFailure cf) {
              /* Quietly ignore completion failures and try again - the type
               * for which the CompletionFailure was thrown shouldn't be completed
               * again by the completer that threw the CompletionFailure.
               */
              return membersOf(c);
          }
      }
docs: Retrieve members of c, ignoring any CompletionFailures that occur.