From pep-0008: Method Names and Instance Variables
Use the function naming rules: lowercase with words separated by underscores as
necessary to improve readability.
During our connections, we are using states to control the Client Socket. We
defined using global variables. In case that we modify this global variable,
we need to change it in serveral parts of the code.
Using enums and declaring a new class, we can redefine the values or create new
states without changing the same code in differents python files.