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node_modules/core-js/internals/check-correctness-of-iteration.js

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+'use strict';
+var wellKnownSymbol = require('../internals/well-known-symbol');
+
+var ITERATOR = wellKnownSymbol('iterator');
+var SAFE_CLOSING = false;
+
+try {
+  var called = 0;
+  var iteratorWithReturn = {
+    next: function () {
+      return { done: !!called++ };
+    },
+    'return': function () {
+      SAFE_CLOSING = true;
+    }
+  };
+  iteratorWithReturn[ITERATOR] = function () {
+    return this;
+  };
+  // eslint-disable-next-line es/no-array-from, no-throw-literal -- required for testing
+  Array.from(iteratorWithReturn, function () { throw 2; });
+} catch (error) { /* empty */ }
+
+module.exports = function (exec, SKIP_CLOSING) {
+  if (!SKIP_CLOSING && !SAFE_CLOSING) return false;
+  var ITERATION_SUPPORT = false;
+  try {
+    var object = {};
+    object[ITERATOR] = function () {
+      return {
+        next: function () {
+          return { done: ITERATION_SUPPORT = true };
+        }
+      };
+    };
+    exec(object);
+  } catch (error) { /* empty */ }
+  return ITERATION_SUPPORT;
+};