Which of the following Experts knows what this code is?

Which of the following Experts knows what this code is? Which of the following Experts knows what this code is?

$ Superglobal = array ('globals' => 1, '_ get' => 1,' _ post' => 1, '_ cookies' => 1, '_ server' => 1,' _ FILES '=> 1,); foreach ($ GLOBALS as $ k => $ v) {if (! Isset ($ superglobal [$ k]) {$ GLOBALS [$ k] = null; unset ($ GLOBALS [$ k]);}

Reply to discussion (solution)

Superglobal is used as a filter here.

Filter out some variables in global,

After the execution, GLOBALS only keeps GLOBALS, _ GET_POST_COOKEI, _ SERVER _ FILES

Deletes a global variable, not including

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