code: def request_error_header(exception):
      
  
      from .conf import options
      
      header = "Bearer realm=\"%s\"" % (options.realm, )
      
      if hasattr(exception, "error"):
          header = header + ", error=\"%s\"" % (exception.error, )
      
      if hasattr(exception, "reason"):
          header = header + ", error_description=\"%s\"" % (exception.reason, )
      
      return header
docs: Generates the error header for a request using a Bearer token based on a given OAuth exception.