Classes

Class for an exception raised when a command execution has been aborted by user (error occured)
Class for an exception raised when a command class is not defined
Class for an exception raised when a command cannot be executed because the associated request is not valid (missing values ?)
Class for an exception raised when a method call is inappropriate

Exceptions

Class for application exceptions
Class for an exception raised when a method parameter is invalid
Class for an exception raised when a command returned value is not defined