module AbstractController::Rendering

def render(*args, &block)

Supported options depend on the underlying +render_to_body+ implementation.

sticks the result in self.response_body.
Normalizes arguments and options, and then delegates to render_to_body and 
def render(*args, &block)
  options = _normalize_render(*args, &block)
  rendered_body = render_to_body(options)
  if options[:html]
    _set_html_content_type
  else
    _set_rendered_content_type rendered_format
  end
  _set_vary_header
  self.response_body = rendered_body
end