I would like to execute some Beahaviours field operations using my Script Listener 
I would like to execute 'setError'.
I managed to make it work (compile?) using following imports
import com.onresolve.jira.groovy.user.FieldBehaviours
import com.onresolve.jira.groovy.user.FormField
import groovy.transform.BaseScript
@BaseScript FieldBehaviours fieldBehaviours
but I get null result when trying to access FormField obj
def formField = getFieldById(getFieldChanged())
or
def formField = getFieldById("customfield_10515")then this following line won't execute correctly because of this null
formField.setError("some text") Any help appreciated 