call func (power up)

    vars:
      extra_task_name: post_task
    tasks:
    - name: pre_task
      desc: this is pre-task
      task:
      - func: shell
        do:
        - echo "hello"
    - name: post_task
      desc: this is post-task
      task:
      - func: shell
        desc: do step1 in shell func
        do:
        - echo "world"
    - name: 2ndtask
      task:
      - func: shell
        desc: to test multiple refs
        do:
        - echo "this is 2nd task"
    - name: task
      desc: this is the task and expect the final message (hello I love this world)
      task:
      - func: shell
        do:
        - echo " I love this "
      - func: call
        desc: use a dynamic var to refer to a task name
        do:
        - '{{.extra_task_name}}'
        - 2ndtask
    

    loading [Config]:  ./tests/functests/upconfig.yml
    Main config:
                 Version -> 1.0.0
                  RefDir -> ./tests/functests
                 WorkDir -> cwd
              AbsWorkDir -> /up_project/up
                TaskFile -> c0104
                 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/c0104
    module: [self], instance id: [dev], exec profile: []
    profile -  envVars:
    
    (*core.Cache)({
    })
    
    Task4: [task ==> task: this is the task and expect the final message (hello I love this world) ]
    -Step1:
    self: final context exec vars:
    
    (*core.Cache)({
      "extra_task_name": "post_task",
      "up_runtime_task_layer_number": 0
    })
    
    cmd( 1):
    echo " I love this "
    
    -
     I love this 
    
    -
     .. ok
    . ok
    -Step2: [: use a dynamic var to refer to a task name ]
    self: final context exec vars:
    
    (*core.Cache)({
      "extra_task_name": "post_task",
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \" I love this \"",
        Code: 0,
        Output: "I love this",
        ErrMsg: ""
      }),
      "up_runtime_task_layer_number": 0
    })
    
    =Task2: [task ==> post_task: this is post-task ]
    --Step1: [: do step1 in shell func ]
    self: final context exec vars:
    
    (*core.Cache)({
      "up_runtime_task_layer_number": 1,
      "extra_task_name": "post_task",
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \" I love this \"",
        Code: 0,
        Output: "I love this",
        ErrMsg: ""
      })
    })
    
    cmd( 1):
    echo "world"
    
    -
    world
    
    -
     .. ok
    . ok
    =Task3: [task ==> 2ndtask:  ]
    --Step1: [: to test multiple refs ]
    self: final context exec vars:
    
    (*core.Cache)({
      "up_runtime_task_layer_number": 1,
      "extra_task_name": "post_task",
      "last_result": (*utils.ExecResult)({
        Cmd: "echo \"world\"",
        Code: 0,
        Output: "world",
        ErrMsg: ""
      })
    })
    
    cmd( 1):
    echo "this is 2nd task"
    
    -
    this is 2nd task
    
    -
     .. ok
    . ok