code: public static ExpressionHandler getHandler(Expression expression) {
          ExpressionHandler ret = null;
          Class<? extends ExpressionHandler> cls = handlers.get(expression.getClass());
          if (cls != null) {
              try {
                  Constructor<? extends ExpressionHandler> con = cls.getConstructor(Expression.class);
                  ret = con.newInstance(expression);
              } catch (Exception e) {
                  log.log(Level.SEVERE, "Failed to instantiate handler for expression '" + expression + "'", e);
              }
          }
          return ret;
      }
docs: This method returns an expression handler for the supplied expression.
  
  @param expression The expression
  @return The handler