Nested bag can't be parsed

[dzvancuks]

Based on bags.robot tests

*** Test Cases ***
Bag with nested bag
    Bag message client
    u8     element       1
    u8     element2      42
    u8     element3      1
    u8     first         12
    u8     second        55
    Client sends message
    Bag message server with minimums with nested bag
    ${msg}=    Server receives message    # Unable to decode bag value.

*** Keywords ***
Bag message client
    New message   ConditionalExample   Example    header:messageType:0xb0b0

Bag message server with minimums with nested bag
    New message   ConditionalExample   Example    header:messageType:0xb0b0
    Start bag    intBag
    case   1      u8    foo    42
    case   1-2    u8    bar    1
    case   *      Nested bag
    End bag

Nested bag
   Start bag    intBag
   case   1      u8    first
   case   1      u8    second     55
   End bag

==============================================================================
Tests                                                                         
==============================================================================
Tests.Test                                                                    
==============================================================================
Bag with nested bag                                                   | FAIL |
Unable to decode bag value.
------------------------------------------------------------------------------
Tests.Test                                                            | FAIL |
1 test, 0 passed, 1 failed
==============================================================================
Tests                                                                 | FAIL |
1 test, 0 passed, 1 failed
==============================================================================