Firstly, this warning has nothing to do with CodeIgniter. NetBeans just gives you a welcome advisory warning that your PHP class is longer than 200 lines (251 lines in your case).
Nothing bad will happen if you receive this message, but you may or may not appreciate it. In any case, it can be configured as follows:
, .
"", "" "". .
, , . - 200 .
:
→ → → .
PHP .
node .
, .
200.
:

, , . , PHP.