title: Inner class function without self
body: <p>Peace, everyone!
  I'm using Python 3.6.3 and I find strange that such construction is possible:</p>
  
  <pre><code>class TestClass(object):
      def __init__(self):
          self.arg = "arg"
  
      def test():
          print("Hey test")
  </code></pre>
  
  <p>And using:</p>
  
  <pre><code>&gt;&gt;&gt; TestClass.test()
  "Hey test"
  </code></pre>
  
  <p>I know that in Python there are standard methods with <code>self</code> as parameter (don't know how to call them properly), static methods, class methods, abstract methods.</p>
  
  <p>But what kind of method the <code>test()</code> is?
  Is it static method?</p>
  
  <hr>
  
  <p>Edited:</p>
  
  <p>Are there any useful usecases of such method of determining a function inside a class?</p>