Gradle task to strip unused packages on Google Play Services library

strip_play_services.gradle

def toCamelCase(String string) {
    String result = ""
    string.findAll("[^\\W]+") { String word ->
        result += word.capitalize()
    }
    return result
}

afterEvaluate { project ->
    Configuration runtimeConfiguration = project.configurations.getByName('compile')
    ResolutionResult resolution = runtimeConfiguration.incoming.resolutionResult
    // Forces resolve of configuration
    ModuleVersionIdentifier module = resolution.getAllComponents().find { it.moduleVersion.name.equals("play-services") }.moduleVersion

    String prepareTaskName = "prepare${toCamelCase("${module.group} ${module.name} ${module.version}")}Library"
    File playServiceRootFolder = project.tasks.find { it.name.equals(prepareTaskName) }.explodedDir

    Task stripPlayServices = project.tasks.create(name: 'stripPlayServices', group: "Strip") {
        inputs.files new File(playServiceRootFolder, "classes.jar")
        outputs.dir playServiceRootFolder
        description 'Strip useless packages from Google Play Services library to avoid reaching dex limit'

        doLast {
            copy {
                from(file(new File(playServiceRootFolder, "classes.jar")))
                into(file(playServiceRootFolder))
                rename { fileName ->
                    fileName = "classes_orig.jar"
                }
            }
            tasks.create(name: "stripPlayServices" + module.version, type: Jar) {
                destinationDir = playServiceRootFolder
                archiveName = "classes.jar"
                from(zipTree(new File(playServiceRootFolder, "classes_orig.jar"))) {
                    exclude "com/google/ads/**"
                    exclude "com/google/android/gms/analytics/**"
                    exclude "com/google/android/gms/games/**"
                    exclude "com/google/android/gms/plus/**"
                    exclude "com/google/android/gms/drive/**"
                    exclude "com/google/android/gms/ads/**"
                }
            }.execute()
            delete file(new File(playServiceRootFolder, "classes_orig.jar"))
        }
    }

    project.tasks.findAll { it.name.startsWith('prepare') && it.name.endsWith('Dependencies') }.each { Task task ->
        task.dependsOn stripPlayServices
    }
}

I paste it to the bottom of app's build.gradle file and it failed : "Cannot get property 'moduleVersion' on null object"
What should I do ?

Cannot get property 'moduleVersion' on null object. I got this problem and the sync failed....

Cannot get property 'moduleVersion' on null object. I got this problem and the sync failed....

at
ModuleVersionIdentifier module = resolution.getAllComponents().find { it.moduleVersion.name.equals("play-services") }.moduleVersion

Happened to me to, so I printed it:
`

ModuleVersionIdentifier module = resolution.getAllComponents().find {
    System.out.println("MODULE NAME ====> " + it.moduleVersion.name);
    /*it.moduleVersion.name.equals("play-services")*/
}.moduleVersion

`
....
MODULE NAME ====> recyclerview-v7
MODULE NAME ====> core
MODULE NAME ====> gson
MODULE NAME ====> hirondelle-date4j
MODULE NAME ====> play-services-analytics
:app:preBuild
:jawampaLib:preBuild
....

As You can see, there is no "play-services", but "play-services-analytics" (in my case) :)

Same happens in my case.