src/main/java/com/arpnetworking/steno/Logger.java
public void warn(
            @Nullable final String event,
            @Nullable final String message,
            @Nullable final Map<String, Object> data) {
        warn(event, message, data, DEFAULT_THROWABLE);
    }
public void warn(
            @Nullable final String event,
            @Nullable final String message,
            @Nullable final Map<String, Object> data) {
        warn(event, message, data, DEFAULT_THROWABLE);
    }
Log a message for a canonical event with supporting key-value pairs at
the warn level.

@since 1.3.0

@param event The canonical event that occurred.
@param message The message to be logged.
@param data Map of data key-value pairs.