Fixes warning: multiple methods named 'postNotificationName:object:' found [-Wstrict-selector-match]
Fixes warning: default label in switch which covers all enumeration values [-Wcovered-switch-default]
Fixes warning: multiple methods named 'objectForKey:' found [-Wstrict-selector-match]
Fixes warning: weak receiver may be unpredictably set to nil [-Wreceiver-is-weak]