| Test |
| LoggerAwareTrait | Basic Implementation of LoggerAwareInterface. |
| LoggerTrait | This is a simple Logger trait that classes unable to extend AbstractLogger (because they extend another class, etc) can include. |
| LoggerAwareInterface | Describes a logger-aware instance. |
| LoggerInterface | Describes a logger instance. |
| AbstractLogger | This is a simple Logger implementation that other Loggers can inherit from. |
| InvalidArgumentException | |
| LogLevel | Describes log levels. |
| NullLogger | This Logger can be used to avoid conditional log calls. |