[Android] Organize your gradle dependencies

build.gradle

ext {

    defaultLinks = [
            kotlin              : "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version",
            appCompat           : 'androidx.appcompat:appcompat:1.0.2',
            core                : 'androidx.core:core-ktx:1.0.2',
            constraintLayout    : 'androidx.constraintlayout:constraintlayout:1.1.3'
    ]

    testLinks = [
            junit           : 'junit:junit:4.12',
            junitExt        : 'androidx.test.ext:junit:1.1.1',
            espresso        : 'androidx.test.espresso:espresso-core:3.2.0',
            mockito         : 'org.mockito:mockito-core:1.10.19',
            mockitoInline   : 'org.mockito:mockito-inline:2.8.47',
            mockitoKotlin   : 'com.nhaarman.mockitokotlin2:mockito-kotlin:2.2.0'
    ]

    retrofitLinks = [
            retrofit            : 'com.squareup.retrofit2:retrofit:2.6.2',
            gson               : 'com.google.code.gson:gson:2.8.5',
            retrofitConverter   : 'com.squareup.retrofit2:converter-gson:2.5.0',
            okHttp             : 'com.squareup.okhttp:okhttp:2.6.0',
            okHttpConverter    : 'com.squareup.okhttp3:logging-interceptor:3.12.1'
    ]

}

static def automaticImplementation (LinkedHashMap links, Closure closure) {
    links.each { key ->
        closure(key.value)
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])

    automaticImplementation (defaultLinks) {
        implementation it
    }

    automaticImplementation (retrofitLinks) {
        implementation it
    }

    automaticImplementation (testLinks) {
        implementation it
    }

}