Cannot store instance of firebaseuser

See more:

Android

authentication

FirebaseAuth mAuth=FirebaseAuth.getReference();

final FirebaseUser annonymsUser;
    mAuth.signInAnnonmously();
    annonymsUser=mAuth.getCurrentUser(); 
    String AnnonymsUserID=annonymsUser.getUid(); // id:OxfVLTclVqNCPq6uTIUUdzxQoar1 
    mAuth.signInWithEmailAndPassword(email,password)...{}
    String userId=mAuth.getCurrentUser().getUid(); // id:LKJDS7jhiudsoiudsdFYT453
   annonmysUser.linkWithCredential(){}  
   String AnnonymsUserID=annonymsUser.getUid();  // id: LKJDS7jhiudsoiudsdFYT453

thus id for annonymsUser geting change after this line

mAuth.signInWithEmailAndPassword(email,password){} though annonymsUser is final

before : OxfVLTclVqNCPq6uTIUUdzxQoar1
 after  : LKJDS7jhiudsoiudsdFYT453

So why cant i store instance at annonymsUser?,and why it is changing though it declared final?

is there any alternate way to store the annonymsUser instance????

What I have tried:

i declared annonymsUser final though it is changing.