Getting 'Cannot resolve method 'addOnCompletionListener()'.......' while trying to place some code inside builder.setPositiveButton's onClick() method
<p>I'm trying to place some code inside <code>AlertDialog.Builder</code>'s <code>builder.setPositiveButton</code> method. </p>

<p>The problem is that I'm getting the following error: <code>Cannot resolve method 'addOnCompletionListener(anonymous android.content.DialogInterface.OnClickListener, anonymous com.google.android.gms.tasks.OnCompletionListener&lt;com.google.firebase.auth.AuthResult&gt;)</code></p>

<p>Here's the code:</p>

<pre><code>    AlertDialog.Builder builder = new AlertDialog.Builder(SignUpActivity.this);
                builder.setTitle("Title");
                builder.setView(R.layout.customlayout);
                builder.setPositiveButton("Continue", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {

//error from below line

                   mAuth.createUserWithEmailAndPassword(userEmail.getText().toString(), userPassword.getText().toString())
                                .addOnCompleteListener(this, new OnCompleteListener&lt;AuthResult&gt;() {
                                    @Override
                                    public void onComplete(@NonNull Task&lt;AuthResult&gt; task) {
                                        Log.d("signUpSuccessful", "createUserWithEmail:onComplete:" + task.isSuccessful());

                                        // If sign in fails, display a message to the user. If sign in succeeds
                                        // the auth state listener will be notified and logic to handle the
                                        // signed in user can be handled in the listener.
                                        if (!task.isSuccessful()) {
                                            Snackbar snackbar = Snackbar
                                                    .make(coordinatorLayout, "Sign up failed. Please retry.", Snackbar.LENGTH_SHORT);
                                            snackbar.show();
                                        }

                                        // ...
                                    }
                                });

//upto this line
                    }
                });
                AlertDialog dialog = builder.create();
                dialog.show();
</code></pre>

<p>What's wrong here?</p>

<p>Please let me know.</p>