Property Value

null if this code element is defined in a third-party assembly.
null if this code element is an interface, an enumeration or an abstract method.
Otherwise returns the number of IL instructions for this code element.

The number of IL instructions can vary depending if an application assembly is compiled in debug or in release mode.
Indeed compiler's optimizations can modify the number of IL instructions.
For example a compiler can add some nop IL instructions in debug mode, to handle Edit and Continue, or to allow attaching an IL instruction to a curly brace.

Reference

ICodeContainer Interface
ICodeContainer Members