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node_modules/core-js/internals/array-species-constructor.js

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+'use strict';
+var isArray = require('../internals/is-array');
+var isConstructor = require('../internals/is-constructor');
+var isObject = require('../internals/is-object');
+var wellKnownSymbol = require('../internals/well-known-symbol');
+
+var SPECIES = wellKnownSymbol('species');
+var $Array = Array;
+
+// a part of `ArraySpeciesCreate` abstract operation
+// https://tc39.es/ecma262/#sec-arrayspeciescreate
+module.exports = function (originalArray) {
+  var C;
+  if (isArray(originalArray)) {
+    C = originalArray.constructor;
+    // cross-realm fallback
+    if (isConstructor(C) && (C === $Array || isArray(C.prototype))) C = undefined;
+    else if (isObject(C)) {
+      C = C[SPECIES];
+      if (C === null) C = undefined;
+    }
+  } return C === undefined ? $Array : C;
+};