title: Rails 5, Undefined method `for' for #<Devise on line devise_parameter_sanitizer.for
body: <p>I am working with Rails 5</p>
  
  <p>I aded new field username in model User.</p>
  
  <pre><code>class Users::RegistrationsController &lt; Devise::RegistrationsController
    before_action :configure_permitted_parameters
  
    protected
  
    def configure_permitted_parameters
      devise_parameter_sanitizer.for(:sign_up).push(:username)  
    end
  end
  </code></pre>
  
  <p>During registration is displayed error: <strong>undefined method `for' for # Did you mean? fork</strong></p>
  
  <p>Trace:</p>
  
  <p>NoMethodError (undefined method `for' for #
  Did you mean?  fork):</p>
  
  <pre><code>app/controllers/users/registrations_controller.rb:7:in `configure_permitted_parameters'
    Rendering /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/diagnostics.html.erb within rescues/layout
    Rendering /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/_source.html.erb
    Rendered /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/_source.html.erb (5.0ms)
    Rendering /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb
    Rendered /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb (2.9ms)
    Rendering /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb
    Rendered /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (1.2ms)
    Rendered /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-5.0.0.rc1/lib/action_dispatch/middleware/templates/rescues/diagnostics.html.erb within rescues/layout (118.1ms)
  </code></pre>
  
  <p>Who can help? How solve this problem?</p>