Base SharedPreferences usage for Kotlin (with dagger2 bonus)

BaseSharedPreferences.kt

abstract class BaseSharedPreferences(
        val preferences: SharedPreferences,
        val moshi: Moshi
) {

    protected fun get(key: String, default: String): String = preferences.getString(key, default)
    protected fun get(key: String, default: Int): Int = preferences.getInt(key, default)
    protected fun get(key: String, default: Float): Float = preferences.getFloat(key, default)
    protected fun get(key: String, default: Long): Long = preferences.getLong(key, default)
    protected fun get(key: String, default: Boolean): Boolean = preferences.getBoolean(key, default)

    protected fun put(key: String, value: String): Unit = preferences.editor { putString(key, value) }
    protected fun put(key: String, value: Int): Unit = preferences.editor { putInt(key, value) }
    protected fun put(key: String, value: Float): Unit = preferences.editor { putFloat(key, value) }
    protected fun put(key: String, value: Long): Unit = preferences.editor { putLong(key, value) }
    protected fun put(key: String, value: Boolean): Unit = preferences.editor { putBoolean(key, value) }

    protected inline fun SharedPreferences.editor(editor: SharedPreferences.Editor.() -> Unit) {
        edit().apply { editor(this) }.apply()
    }

    @Suppress("IMPLICIT_CAST_TO_ANY")
    protected inline fun <reified T> getObject(key: String): T? {
        val prefs = preferences
        val json = prefs.getString(key, Prefs.PREF_DEF_STRING)
        return if(json != EMPTY_STRING) moshi.fromJson(T::class.java, json) else null
    }

    protected inline fun <reified T> putObject(key: String, value: T) {
        val prefs = preferences
        prefs.edit().apply {
            val jsonValue = if(value == null) Prefs.PREF_DEF_STRING else moshi.toJson(T::class.java, value)
            putString(key, jsonValue)
        }.apply()
    }

    protected inline fun editMultiple(doStuff: () -> Unit) {
        val prefs = preferences
        prefs.edit().apply {
            doStuff()
        }.apply()
    }

    protected fun hasPreference(key: String) = preferences.contains(key)
}

PrefsApp.kt

class PrefsApp(
        preferences: SharedPreferences,
        moshi: Moshi
): BaseSharedPreferences(preferences, moshi) {

    private val FIRST_RUN = "FIRST_RUN"
    private val USER_DEVICE_ID = "USER_DEVICE_ID"
    private val REALM_KEY = "REALM_KEY"
    private val PREFS_KEY = "PREFS_KEY"
    
    var firstRun: Boolean
        get() = get(FIRST_RUN, true)
        set(value) = put(FIRST_RUN, value)

    var realmKey: String
        get() = get(REALM_KEY, Prefs.PREF_DEF_STRING)
        set(value) = put(REALM_KEY, value)

    var prefsKey: String
        get() = get(PREFS_KEY, Prefs.PREF_DEF_STRING)
        set(value) = put(PREFS_KEY, value)

    var deviceId: String
        get() = get(USER_DEVICE_ID, Prefs.PREF_DEF_STRING)
        set(value) = put(USER_DEVICE_ID, value)
}

SharedPreferencesModule.kt

@Module
class SharedPreferencesModule {

    @Provides
    @AppScope
    fun providePreferences(appContext: Application): SharedPreferences {
        return PreferenceManager.getDefaultSharedPreferences(appContext)
    }

    @Provides
    @AppScope
    fun provideAppPreds(
            preferences: SharedPreferences,
            moshi: Moshi
    ): PrefsApp = PrefsApp(preferences, moshi)

where is moshi.toJson ?