cannot reslve DatabaseReference code example
Example: Cannot resolve method 'getInstance' in 'FirebaseDatabase'
implementation 'com.google.firebase:firebase-analytics:17.2.1'
implementation 'com.google.firebase:firebase-database:19.2.0'
implementation 'com.google.firebase:firebase-analytics:17.2.1'
implementation 'com.google.firebase:firebase-database:19.2.0'