TypeError · Unable to get property 'apply' of undefined or null referenc

[Alex Oxte]

--
function wrapNativeArrayMethod(methodName, wrapper) {
  | var nativeFn = Array.prototype[methodName];
  | return function (arr, f, context, argsLen) {
  | var args = new Array(2);
  | assertArgument(argsLen > 0);
  | args[0] = wrapper(f, context);
  | args[1] = context;

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