log/field.go
func Error(err error) Field {
	return Field{
		key:          "error",
		fieldType:    errorType,
		interfaceVal: err,
	}
}
func Error(err error) Field {
	return Field{
		key:          "error",
		fieldType:    errorType,
		interfaceVal: err,
	}
}
func Error ( err error ) Field { return Field { key : " " , fieldType : errorType , interfaceVal : err , } }
// Error adds an error with the key "error" to a Span.LogFields() record
Error adds an error with the key error to a Span . LogFields () record