How do we create ann Interface using Webrick

I have created the following interface but while connecting the client
throws
=> ““Method ExecuteTest missing or wrong number of parameters!”” error

INTERFACE = XMLRPC::interface(“srv”) {
meth ‘string ExecuteTest(string, string)’, ‘Execute tests’,
‘execute’
}

have created a handler too as follows:

rpcserver.add_handler(SimpleXMLRPC::INTERFACE,SimpleXMLRPC.new)

Am I missing something ???