() { return new ArrayBuffer(10); },
        {"Content-Type": "application/xml;charset=ASCII"},
        "application/xml;charset=ASCII",
        "ArrayBuffer request keeps setRequestHeader() Content-Type and charset"
      )
      request(
        function _Uint8Array() { return new Uint8Array(new ArrayBuffer(10)); },
        {"Content-Type": ""},
        "",
        'ArrayBufferView request respects setRequestHeader("")'
      )
      request(
        function _Uint8Array() { return new Uint8Array(new Array