Jira transition validator... will restrict transition if any issue is waiting in 'Testing' state for the given team.Thanks to examples like https://answers.atlassian.com/questions/134531/how-to-run-jql-query-inside-groovy-script

restrictWipJiraValidator.groovy

def user = componentManager.jiraAuthenticationContext.getLoggedInUser()
def campoCelula = componentManager.customFieldManager.customFieldObjects.find { it.fieldName.endsWith('lula IT') }
def celula = issue.getCustomFieldValue(campoCelula)
def jql = """
  project = 'TICKETBIS'
  and '${campoCelula.name}' = '${celula}'
  and status = 'En Pruebas'
  and assignee is null
"""
def searchService = componentManager.getSearchService()
def query = searchService.parseQuery(user, jql).getQuery()
def searchResult = searchService.search(user, query, com.atlassian.jira.web.bean.PagerFilter.unlimitedFilter)
def issuesEnPruebas = searchResult.issues.collect {
        componentManager.issueManager.getIssueObject(it.id)
}

if (issuesEnPruebas.size() > 0) {
  println "CM: ${issue}, ${user}"
  invalidInputException = new com.opensymphony.workflow.InvalidInputException("Peticiones para probar antes de empezar nuevas? (${issuesEnPruebas})")
}