Jenkins pipeline unit test Unable to mock wrap method

I am trying to test this code:

vars/checkconfig.groovy

import com.pipeline.CheckConfig

def call(def map) {
  CheckConfig checkConfig = new CheckConfig(this);
  checkConfig.run(map);
}

com/pipeline/CheckConfig.groovy

class CheckConfig implements Serializable {

  def script

  CheckConfig(script) {
    this.script = script
  }

  void run(def configMap) {
    script.wrap([$class: 'BuildUser']) {
      script.properties([script.buildDiscarder(script.logRotator(artifactDaysToKeepStr: '', artifactNumToKeepStr: '', daysToKeepStr: '', numToKeepStr: '2'))])
      if (script.currentBuild.buildCauses.shortDescription.contains("Branch indexing")) {
        script.currentBuild.result = BuildStatus.ABORTED
        script.error("Aborting build from branch indexing. Nothing to be built by any user or webhook (git push)")
      }
    }

    setUpPipeline(configMap)
    new BuildNotification(script).notifyBuild(BuildStatus.STARTED)

  }
....
}

And my test:

class CheckConfigTest extends BasePipelineTest{
    // Before every testcase is run, do this:
    @Before
    void setUp() {
      scriptRoots += 'vars'
      super.setUp()
    }

    @Test
    void 'Check config command'() {
        //helper.registerAllowedMethod("wrap", [Map.class], {m->return m})
        def script = loadScript('vars/checkConfig.groovy')
        script.call([:])
        printCallStack()
    }

}

It is throwing the following error:

groovy.lang.MissingMethodException: No signature of method: checkConfig.wrap() is applicable for argument types: (LinkedHashMap, com.avoristravel.pipeline.CheckConfig$_run_closure1) values: [[$class:BuildUser], com.avoristravel.pipeline.CheckConfig$_run_closure1@780c39e3]
Possible solutions: grep(), wait(), run(), run(), dump(), grep(java.lang.Object)

Is it possible to mock the wrap method from the build user vars plugin?