<?php 
 
$empty_func = function($a){ 
 
 
}; 
 
$new_arr = array_map(function($a) {return $a[0];}, $argv); 
 
$callback = function($b){return $b['id'];}; 
 
$long_callback = function($c)use ($d,&$e){ 
    return $c['id']; 
}; 
 
function doSomething($a,$b) { 
    echo 'Hello world!'; 
} 
 
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