How do you fit blocks into a procedure block?

procedures_callreturn
How do I get a procedure block like this? With the open space for a block.

right click on the block ,select inline inputs

See http://www.appinventor.org/bookChapters/chapter21.pdf
from
App Inventor 2 Book: Create Your Own Android Apps
from
FAQ Section: Books, Tips, Tutorials for AI2

proceduremutator