question: @ Nullable public static < R > R wrapThreadLoader ( ClassLoader ldr , Callable < R > c ) throws IgniteCheckedException { Thread curThread = Thread . currentThread ( ) ; ClassLoader ctxLdr = curThread . getContextClassLoader ( ) ; try { curThread . setContextClassLoader ( ldr ) ; return c . call ( ) ; } catch ( IgniteCheckedException | RuntimeException e ) { throw e ; } catch ( Exception e ) { throw new IgniteCheckedException ( e ) ; } finally { curThread . setContextClassLoader ( ctxLdr ) ; } }
target:  Sets thread context class loader to the given loader, executes the closure, and then resets thread context class loader to its initial value.