String getThreadName() {
      String firstLine = lines.get(0);
      int quote = firstLine.indexOf('"', 1);
      if (quote > 1) {
        return firstLine.substring(1, quote);
      }
      return firstLine.substring(1);
    }
create a stack with the given initial lines, reading the rest from the Reader
geode-core/src/main/java/org/apache/geode/internal/util/PluckStacks.java