want    uint64
		wantErr string
	}
	tests := []testCase{
		{"x", 0, "invalid byte in chunk length"},
		{"0000000000000000", 0, ""},
		{"0000000000000001", 1, ""},
		{"ffffffffffffffff", 1<<64 - 1, ""},
		{"FFFFFFFFFFFFFFFF", 1<<64 - 1, ""},
		{"000000000000bogus", 0, "invalid byte in chunk length"},
		{"00000000000000000", 0, "http chunk length too large"}, // could accept if we wanted

        // Test various long values
        assertEquals("0000000000000000", Hexdump.toHexString(0L, 16));
        assertEquals("00000000000000FF", Hexdump.toHexString(255L, 16));
        assertEquals("FFFFFFFFFFFFFFFF", Hexdump.toHexString(-1L, 16));

        // Test different sizes
        assertEquals("00000000", Hexdump.toHexString(0L, 8));
        assertEquals("12345678", Hexdump.toHexString(0x12345678L, 8));
    }