module Roda::RodaPlugins::SinatraHelpers::ResponseMethods

def body(value = (return @body unless defined?(yield); nil), &block)

evaluation is deferred until the body is needed.
Set or retrieve the response body. When a block is given,
def body(value = (return @body unless defined?(yield); nil), &block)
  if block
    @body = DelayedBody.new(&block)
  else
    self.body = value
  end
end