title: How to import BR class while implementing two way data binding? Importing BR shows error in my code
body: <p>I am inheriting BaseObservable class. In 'notifyPropertyChanged' method when i am passing integer fieldId, 'BR' class shows red error.
  I am trying to implement two-way data binding.</p>
  
  <p><strong>ViewModel.java</strong></p>
  
  <pre><code>package com.example.test;
  
  import android.databinding.BaseObservable;
  import android.databinding.Bindable;
  
  public class ViewModel extends BaseObservable {
  String username;
  String password;
  
  @Bindable
  public String getUsername() {
      return username;
  }
  public void setUsername(String username) {
      this.username = username;
      notifyPropertyChanged(BR.username);
  }
  @Bindable
  public String getPassword() {
      return password;
  }
  
  public void setPassword(String password) {
      this.password = password;
      notifyPropertyChanged(BR.password);
  }
  }
  </code></pre>