title: Analog of template toolkit block-include in erb rails
body: <p>What is the analog of template toolkit block-include in erb rails?
  Or how to translate this code to rails erb (only one single file): </p>
  
  <pre><code>[% BLOCK hello %]
     Hello [% var %]!
  [% END %]
  [% INCLUDE hello var='World' %]
  </code></pre>
  
  <p>result:</p>
  
  <pre><code>   Hello World!
  </code></pre>