title: How to inherit from NilClass or how to simulate similar function
body: <p>I just want to use Null Object Design Pattern, but I found I can inherit from NilClass.</p>
  
  <p>I can write a method "nil?" and return false but what if user write code below</p>
  
  <pre><code>if null_object 
    puts "shouldn't be here"
  end
  </code></pre>
  
  <p>For clarify what I try to do is:</p>
  
  <pre><code>record = DB.find(1)
  # if it can not find record 1, the bellow code should not raise exception
  record.one_attr 
  # and what's more
  if record 
    puts "shouldn't be here"
  end
  # I don't want to override all NilClass
  </code></pre>