logger: document that keys are always strings
@@ -47,7 +47,7 @@ type Logger interface {
Level() LogLevel
// Log logs a message with key, value pair arguments for the given log
- // level.
+ // level. Keys are always strings, while values can be any type.
//
// This must be safe to call concurrently.
Log(level LogLevel, msg string, keyvals ...interface{})
