getting BUG! exception in phase 'semantic analysis' in source unit 'Script1.groovy'

Hi All. I'm working on the script library in readyAPI 2.8.0

I have a readyAPI project saved in C/soapui and I've created a folder called GroovyLibrary inside the project folder (C/soapui/GroovyLibrary). I place my below script inside the groovyLibrary folder.

package soapui .GroovyLibrary

class Callee
{
String hello()
{
return "Hello world!"
}
def static salute( who, log ) { log.info "Hello again $who!" }}

I followed the exact the way it mentioned in the below documentation

https://support.smartbear.com/readyapi/docs/testing/scripts/library.html#_ga=2.210636115.718279044.1573586134-774997694.1532459669

but while executing the groovy from readyAPI; I'm getting below execption 

BUG! exception in phase 'semantic analysis' in source unit 'Script2.groovy' The lookup for Callee caused a failed compilaton. There should not have been any compilation from this call.

How can I rectify this? anyhelp would be appreciated.

Thanks.