Android/Kotlin: Error: "Expecting a Top Level Declaration > Task: App: buildInfoGeneratorDebug"

I try to write a class to manage a SQLite DB, but I have the error message "Expecting a top level declaration > Task :app:buildInfoGeneratorDebug".

   package com.xexxxwxxxxs.GMP

    import android.database.sqlite.SQLiteDatabase
    import android.database.sqlite.SQLiteOpenHelper
    import android.content.Context
    import android.content.ContentValues

    class DBHandler(context: Context, name: String?, factory: SQLiteDatabase.CursorFactory?, version: Int) : SQLiteOpenHelper(context, DATABASE_NAME, factory, DATABASE_VERSION)
    {
        override fun onCreate(db: SQLiteDatabase)
        {

        }

        override fun onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int)
        {

        }

        companion object
        {
            private val DATABASE_VERSION = 1
            private val DATABASE_NAME = "GMP.db"
        }
    } 

Do you have any ideas?

Thanks in advance