Create different sourcecode

Core code:

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }

        include {
        }

        exclude {
        }
    }

You can custom your code under the include/java folder.

Select sourcecode when coding

You should select the build variants(include, exclude) from Android Studio to ensure your code works correctly.

The variant selection is normally in the bottom-left side of Android Studio named Build Variants.