Groovy scripts: how to import another groovy file?

Setup, Configuration and Use Scripts & Rules
11

Modifiying org.openhab.automation.groovyscripting.internal.GroovyScriptEngineFactory would do the trick.

public class GroovyScriptEngineFactory extends AbstractScriptEngineFactory {

    private final org.codehaus.groovy.jsr223.GroovyScriptEngineFactory factory = new org.codehaus.groovy.jsr223.GroovyScriptEngineFactory();
....
    @Override
    public @Nullable ScriptEngine createScriptEngine(String scriptType) {
        if(scriptTypes.contains(scriptType)) {
            org.codehaus.groovy.jsr223.GroovyScriptEngineImpl engine = (org.codehaus.groovy.jsr223.GroovyScriptEngineImpl) factory.getScriptEngine();
            engine.getClassLoader().addClasspath("/path/to/lib");
            return engine;
        }
        return null;
    }
}

Edit: fixed addPath to addClasspath