title: I'm trying to use a @classmethod with filter() in ndb and receiving a error. NDB newbie
body: <p>I have a custom User model with this classmethod.:</p>
  
  <pre><code>@classmethod
  def by_name(cls, name):
      u = User.query().filter('name =', name).get()
      return u
  </code></pre>
  
  <p>And I am getting this error.:</p>
  
  <pre><code>TypeError('Cannot filter a non-Node argument; received %r' % arg)
  </code></pre>
  
  <p>This is My first time using NDB and the code worked with db and all(). So I know this is a simple fix.</p>
  
  <p>Thanks in advance.</p>