module Gitlab::Client::Notes

def note_content(body)

in the 'else'.
TODO: Remove this method after a couple deprecation cycles. Replace calls with the code

def note_content(body)
  if body.is_a?(Hash)
    warn 'Passing the note body as a Hash is deprecated.  You should just pass the String.'
    body
  else
    { body: body }
  end
end