Method toString

classpath/java/util/regex/Compiler.java:326–334

()

    }

    public String toString() {
      String inner = group.toString();
      if (inner.startsWith("(?:")) {
        inner = inner.substring(3);
      } else {
        inner += ")";
      }
      return "(?=" + inner;
    }
  }

  private class Group0 extends Expression {