code: public void printSolverState(final PrintStream output) {
          output.println("level=" + this.level);
          output.println("next=" + this.next);
          output.println("ignore=" + this.ignore);
          output.println("empty=" + this.empty);
          output.println("vars=" + this.vars);
          output.println("vals=" + this.vals);
          output.println("phases=" + this.phases);
          output.println("decisions=" + this.decisions);
          output.println("control=" + this.control);
          output.println("watches=" + this.watches);
          output.println("trail=" + this.trail);
          output.println("frames=" + this.frames);
      }
docs: Prints the current solver state to a given output stream.
  @param output the output stream