```
irb(main):003:0> def foo_method; end
irb(main):007:0> foo_method(&Proc.new)
ArgumentError: tried to create Proc object without a block
	from (irb):7:in `new'
	from (irb):7
	from /Users/ecarey/.rbenv/versions/2.1.0/bin/irb:11:in `<main>'
```