slf4j-timber/src/main/java/org/slf4j/impl/TimberAndroidLoggerAdapter.java
public void error(String format, Object arg) {
        formatAndLog(Log.ERROR, format, arg);
    }
public void error(String format, Object arg) {
        formatAndLog(Log.ERROR, format, arg);
    }
Log a message at the ERROR level according to the specified format and
argument.
<p>
<p>
This form avoids superfluous object creation when the logger is disabled
for the ERROR level.
</p>

@param format the format string
@param arg    the argument