Correts handling of the special HTTP/S response code header which comes first
Corrects usage of global namespace Exception classes
Corrects call to parent constructor (typeo)
Adds a TODO comment
Adds a call to parent constructor to make sure the headers property is properly initialized
Corrects Exception namespacing, rearranges code, and fills out implementation on respond() method
Corrects call to ReflectionMethod instead of ReflectionProperty since it is executed against a method name
Adds a working REST API example. Hopefully it makes sense.