add docblock

Author: stancl

src/VirtualColumn.php

@@ -140,9 +140,14 @@ public static function getCustomColumns(): array
         ];
     }
 
+    /**
+     * Get a column name for an attribute that can be used in SQL queries.
+     *
+     * (`foo` or `data->foo` depending on whether `foo` is in custom columns)
+     */
     public function getColumnForQuery(string $column): string
     {
-        if (in_array($column, static::getCustomColumns())) {
+        if (in_array($column, static::getCustomColumns(), true)) {
             return $column;
         }