summary: Unknown
description: |
  Unknown error.  For example, this error may be returned when
  a `Status` value received from another address space belongs to
  an error space that is not known in this address space.  Also
  errors raised by APIs that do not return enough error information
  may be converted to this error.

  HTTP Mapping: 500 Internal Server Error
value:
  error:
    code: 2
    status: UNKNOWN
    message: Unknown error