code: private void updateGlue(final CLClause c) {
          if (!this.config.glueupdate) { return; }
          if (!this.config.gluered) {
              assert c.glue() == 0;
              return;
          }
          assert this.frames.empty();
          for (int i = 0; i < c.lits().size(); i++) { markFrame(c.lits().get(i)); }
          final int newGlue = unmarkFrames();
          if (newGlue >= c.glue()) { return; }
          c.setGlue(newGlue);
          this.stats.gluesSum += newGlue;
          this.stats.gluesCount++;
          this.stats.gluesUpdates++;
      }
docs: Updates the glue value for a given clause.
  @param c the clause