code: public static String[] getParameters(String function){
          if(function==null){return new String[]{};}
          function = function.substring(function.indexOf("(",5)+1, function.indexOf(")",1));
          return function.split(",");
      }
docs: Get parameters from functions
  functions are usually as func(CONCAT_DATE(sf,sTo)) or func(ARITH(pre,tes,%))
  @param function
  @return