def save(activity_uri = nil, update_etag = false)
      response = super(@content, headers)
      @rdf_subject ||= response.env.response_headers['location']
      http_head(true) if update_etag
      return response unless activity_uri
      rdf_source.wasGeneratedBy = activity_uri
      rdf_source.save
      response
    end
def save(activity_uri = nil, update_etag = false)
      response = super(@content, headers)
      @rdf_subject ||= response.env.response_headers['location']
      http_head(true) if update_etag
      return response unless activity_uri
      rdf_source.wasGeneratedBy = activity_uri
      rdf_source.save
      response
    end
Saves over LDP, passing #content and #headers to the request.

 @param activity_uri  the activity responsible for generation
 @param update_etag  forces an http_head request to update of the etag
 @raise (see Krikri::LDP::Resource#save)
 @return [Boolean] true for success; else false

 @see Krikri::LDP::Resource#save