multiple layers overriding

    vars:
      global_a: aaa
      global_b: bbb
    tasks:
    - name: task
      task:
      - func: call
        vars:
          local_a: aaa
          local_b: bbb
          tom: my name is tom
        do:
        - subtask1
    - name: subtask1
      task:
      - func: cmd
        do:
        - name: print
          cmd: '{{.tom}}'
        - name: assert
          cmd:
          - '{{eq .tom "my name is tom"}}'
      - func: cmd
        vars:
          tom: 'hi i am tom'
        do:
        - name: print
          cmd: '{{.tom}}'
        - name: assert
          cmd:
          - '{{eq .tom "my name is tom"}}'
      - func: call
        do:
        - subtask2
    - name: subtask2
      task:
      - func: cmd
        do:
        - name: print
          cmd: '{{.tom}}'
        - name: assert
          cmd:
          - '{{eq .tom "my name is tom"}}'
      - func: cmd
        vars:
          tom: 'hi i am tom'
        do:
        - name: print
          cmd: '{{.tom}}'
        - name: assert
          cmd:
          - '{{eq .tom "my name is tom"}}'
    

    loading [Config]:  ./tests/functests/upconfig.yml
    Main config:
                 Version -> 1.0.0
                  RefDir -> ./tests/functests
                 WorkDir -> cwd
              AbsWorkDir -> /up_project/up
                TaskFile -> c0112
                 Verbose -> vvv
              ModuleName -> self
               ShellType -> /bin/sh
           MaxCallLayers -> 8
                 Timeout -> 3600000
     MaxModuelCallLayers -> 256
               EntryTask -> task
      ModRepoUsernameRef -> 
      ModRepoPasswordRef -> 
    work dir: /up_project/up
    -exec task: task
    loading [Task]:  ./tests/functests/c0112
    module: [self], instance id: [dev], exec profile: []
    profile -  envVars:
    
    (*core.Cache)({
    })
    
    Task1: [task ==> task:  ]
    -Step1:
    self: final context exec vars:
    
    (*core.Cache)({
      "global_a": "aaa",
      "global_b": "bbb",
      "up_runtime_task_layer_number": 0,
      "tom": "my name is tom",
      "local_a": "aaa",
      "local_b": "bbb"
    })
    
    =Task2: [task ==> subtask1:  ]
    --Step1:
    self: final context exec vars:
    
    (*core.Cache)({
      "global_a": "aaa",
      "global_b": "bbb",
      "up_runtime_task_layer_number": 1,
      "tom": "my name is tom",
      "local_a": "aaa",
      "local_b": "bbb"
    })
    
    ~~SubStep1: [print:  ]
    my name is tom
    ~~SubStep2: [assert:  ]
     1 ASSERT OK:     [{{eq .tom "my name is tom"}}]
    --Step2:
    self: final context exec vars:
    
    (*core.Cache)({
      "local_b": "bbb",
      "global_a": "aaa",
      "global_b": "bbb",
      "up_runtime_task_layer_number": 1,
      "local_a": "aaa",
      "tom": "my name is tom"
    })
    
    ~~SubStep1: [print:  ]
    my name is tom
    ~~SubStep2: [assert:  ]
     1 ASSERT OK:     [{{eq .tom "my name is tom"}}]
    --Step3:
    self: final context exec vars:
    
    (*core.Cache)({
      "tom": "my name is tom",
      "local_a": "aaa",
      "local_b": "bbb",
      "global_a": "aaa",
      "global_b": "bbb",
      "up_runtime_task_layer_number": 1
    })
    
    ==Task3: [task/subtask1 ==> subtask2:  ]
    ---Step1:
    self: final context exec vars:
    
    (*core.Cache)({
      "tom": "my name is tom",
      "local_a": "aaa",
      "local_b": "bbb",
      "global_a": "aaa",
      "global_b": "bbb",
      "up_runtime_task_layer_number": 2
    })
    
    ~~~SubStep1: [print:  ]
    my name is tom
    ~~~SubStep2: [assert:  ]
     1 ASSERT OK:     [{{eq .tom "my name is tom"}}]
    ---Step2:
    self: final context exec vars:
    
    (*core.Cache)({
      "local_a": "aaa",
      "local_b": "bbb",
      "global_a": "aaa",
      "tom": "my name is tom",
      "global_b": "bbb",
      "up_runtime_task_layer_number": 2
    })
    
    ~~~SubStep1: [print:  ]
    my name is tom
    ~~~SubStep2: [assert:  ]
     1 ASSERT OK:     [{{eq .tom "my name is tom"}}]