code: function (self/*, args*/) {
      if (self.__hasWrittenBody__) {
        throw new Error('require_self can only be called once per source file');
      }
  
      self.context.requireAsset(self.pathname);
      self.processSource();
  
      prop(self, '__hasWrittenBody__', true);
      self.includedPathnames = [];
    }
docs: `require_self` causes the body of the current file to be inserted before any subsequent `require` or `include` directives. Useful in CSS files, where it's common for the index file to contain global styles that need to be defined before other dependencies are loaded.  /*= require "reset" *= require_self *= require_tree .