shouldLog method
This method checks every message
Displays a message if true
is returned,
and not display if false
Implementation
@override
bool shouldLog(dynamic msg, LogLevel level) {
final currLogLevelIndex = logLevelPriorityList.indexOf(logLevel);
final msgLogLevelIndex = logLevelPriorityList.indexOf(level);
return currLogLevelIndex >= msgLogLevelIndex;
}