Always use retry inside rescue blocks
Ruby includes a retry keyword that would bring execution back to the start of the current method while preserving scope. 
But what if you do this?
def my_method
  my_var = 1
  retry
end
That would fail with an Invalid retry, which is one of the few illegal statements in Ruby.
retry is only allowed inside rescue blocks.
def my_method
  my_var = 1
  raise Exception
rescue Exception
  retry
end
