code: public boolean popTable() {
          if (currentLevel > 0) {
              //Remove all the variable having a level equals to currentLevel
              for (Iterator<Map.Entry<String, Integer>> ite = level.entrySet().iterator(); ite.hasNext(); ) {
                  Map.Entry<String, Integer> e = ite.next();
                  if (e.getValue() == currentLevel) {
                      ite.remove();
                      type.remove(e.getKey());
                  }
              }
              currentLevel--;
              return true;
          }
          return false;
      }
docs: Pop the table.
  Every variable created after the last pushTable() are removed from the table. The
  table can not be poped if it was not at least pushed once earlier.
  
  @return {@code true} if the table has been popped successfully. {@code false} otherwise