This file is an empty file in order to test dynamic plugin engine.
For this purpose, we test four part in this engine:
I.   Test path loading engine
II. Test registering engine 

I.   Test path loading engine 
    In the dynamic plugin engine, we can add a path to load modules, but this 
  path must be a directory path.So we tempt to add a file path and a unknown 
  path in order to raise errors. We tempt to add a directory path to check if 
  the engine runs.
 
II. Test registering engine
    In this part, we try to register some functions with dynamic engine and
  to apply them. For this purpose, we test with a mutual recursive function
  separated in two files. This test is also an example of how to write a good 
  dynamic plugin.