block_given.rb

def should(&a_block_that_is_never_called)
  stash_block {
    puts "block_given? is #{block_given?}."
  }
end

def stash_block(&block)
  $block = block
end

def call_stashed_block_without_taking_a_block_yourself
  $block.call
end

should do "something, but not in this test" end
call_stashed_block_without_taking_a_block_yourself