Accessing development environment information
Avoid the following methods, as they make references to information that is essentially provided only for the development environment: 
•classPool 
•instVarNames 
•sharedPools 
•Library management methods, such as controller, timestamp, and extended 
If you attempt to access this information in a packaged image produced by a standard runtime instruction, the attempt will fail because this information is automatically excluded by that instruction. 
Last modified date: 04/26/2019