<io_command>       ::= <addparam_cmd> | <getlistlen_cmd> | <addresult_cmd> | <getparamlist_cmd>
<addparam_cmd>     ::= "addParam(" <stringliteral> "," <identifier> ")"
<getlistlen_cmd>   ::= "getListLen(" <identifier> "," <identifier> ")"
<getparamlist_cmd> ::= "getQueryParamList(" <stringliteral> "," <identifier> ")"
<addresult_cmd>    ::= "addResult(" <identifier> ")"