{bucketName: "unused-bucket", objName: "def", uploadID: "xyz", PartID: 1, expectedError: fmt.Errorf("%s", "Invalid upload id xyz")},
		// Test Case - 8.
		// Existing bucket, object name different from which NewMultipartUpload is constructed from.
		// Expecting "Invalid upload id".
		{bucketName: bucket, objName: "def", uploadID: "xyz", PartID: 1, expectedError: fmt.Errorf("%s", "Invalid upload id xyz")},
		// Test Case - 9.

	{"", "", -1},
	{"", "a", -1},
	{"", "abc", -1},
	{"a", "", -1},
	{"a", "a", 0},
	{"\x80", "\xffb", 0},
	{"aaa", "a", 0},
	{"abc", "xyz", -1},
	{"abc", "xcz", 2},
	{"ab☺c", "x☺yz", 2},
	{"a☺b☻c☹d", "cx", len("a☺b☻")},
	{"a☺b☻c☹d", "uvw☻xyz", len("a☺b")},
	{"aRegExp*", ".(|)*+?^$[]", 7},
	{dots + dots + dots, " ", -1},
	{"012abcba210", "\xffb", 4},
	{"012\x80bcb\x80210", "\xffb", 3},

golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
gomodules.xyz/jsonpatch/v2 v2.4.0 h1:Ci3iUJyx9UeRx7CeFN8ARgGbkESwJK+KB9lLcWxY/Zw=
gomodules.xyz/jsonpatch/v2 v2.4.0/go.mod h1:AH3dM2RI6uoBZxn3LVrfvJ3E0/9dG4cSrbuBJT4moAY=
google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=

		t.Fatalf("Unable to create file, %s", err)
	}
	if err = xlStorage.AppendFile(context.Background(), "success-vol", "abc/xyz/ghi/success-file", []byte("Hello, world")); err != nil {
		t.Fatalf("Unable to create file, %s", err)
	}

	testCases := []struct {
		srcVol  string
		srcPath string
		// expected result.

				"audio/x-wav",
				"chemical/x-cdx",
				"chemical/x-cif",
				"chemical/x-cmdf",
				"chemical/x-cml",
				"chemical/x-csml",
				"chemical/x-pdb",
				"chemical/x-xyz",
				"image/x-ms-bmp",
				"image/cgm",
				"image/example",
				"image/fits",
				"image/g3fax",
				"image/gif",
				"image/ief",
				"image/jp2",
				"image/jpeg",
				"image/jpm",