code: func vimSoapFault(err error) (types.AnyType, bool) {
  	if sf, ok := soapFault(err); ok {
  		return sf.VimFault(), true
  	}
  	return nil, false
  }
docs: // vimSoapFault extracts the VIM fault. Check the returned boolean value to see
  // if you have a fault, which will need to be further asserted into the error
  // that you are looking for.