(command.CommandList
  children: [
    (command.AndOr
      ops: [Op_DAmp]
      children: [
        (C {(Lit_Other '[')} 
          {
            (word_part.BracedVarSub
              token: <VSub_Name LOGGER_SH>
              suffix_op: (suffix_op.StringUnary op_id:VTest_Plus arg_word:{(true)})
            )
          } {(Lit_Other ']')}
        )
        (command.ControlFlow token:<ControlFlow_Return return>)
      ]
    )
    (command.Assignment
      keyword: Assign_Declare
      flags: [-g]
      pairs: [(assign_pair lhs:(lhs_expr.LhsName name:LOGGER_SH) op:Equal rhs:{(true)})]
    )
    (C {(.)} 
      {
        (word_part.BracedVarSub
          token: <VSub_Name BASH_SOURCE>
          suffix_op: (suffix_op.StringUnary op_id:VOp1_Percent arg_word:{(Lit_Slash /) ('*')})
        ) (/common.sh)
      }
    )
    (command.Assignment
      keyword: Assign_Declare
      flags: [-g]
      pairs: [(assign_pair lhs:(lhs_expr.LhsName name:LOGGER_FILE) op:Equal rhs:{(DQ (logfile.txt))})]
    )
    (command.SimpleCommand
      words: [{(echo)}]
      redirects: [
        (redir.Redir
          op: <Redir_Great '>'>
          fd: 16777215
          arg_word: {(DQ (${ VSub_Name LOGGER_FILE))}
        )
      ]
    )
    (command.FuncDef
      name: log
      body: 
        (command.BraceGroup
          children: [
            (command.SimpleCommand
              words: [{(echo)} {(DQ (${ VSub_At '@'))}]
              redirects: [
                (redir.Redir
                  op: <Redir_DGreat '>>'>
                  fd: 16777215
                  arg_word: {(DQ (${ VSub_Name LOGGER_FILE))}
                )
              ]
            )
          ]
        )
    )
  ]
)