This is a template!

What happens when we lock two different consequent sub blocks:


  This is mixed: mixed1!

  This is mixed: mixed3!


Now comes sub2:


  This is mixed: mixed2!

  This is mixed: mixed4!


As you can see to make mixed rows we really have to enclose
them both in a third sub block. When instance is called
the output is added to where the template is.

There are actually two different ways to lock a sub blocks -
front or back. Lets demonstrate it with a confusing example.

 Counting: 9
 Counting: 8
 Counting: 7
 Counting: 6
 Counting: 5
 Counting: 0
 Counting: 1
 Counting: 2
 Counting: 3
 Counting: 4


By default the locking happens at end. In practice you rarely
need locking at front but it is useful sometimes.