[+!] all but small

some small modifications, tests added

examples/start_client.bat

@@ -0,0 +1,10 @@
+@echo off
+setlocal
+cd /d "%~dp0.."
+set "PYTHON=D:\_Programs\anaconda\envs\sites\python.exe"
+if not exist "%PYTHON%" (
+    echo Python not found: %PYTHON%
+    exit /b 1
+)
+"%PYTHON%" -u "%~dp0client.py" %*
+exit /b %ERRORLEVEL%