content: sub trace(msg_ as String, data_ = invalid)
    if m.loggerCat <> invalid then
      category_ = m.loggerCat
    else if m.top <> invalid then
      category_ = m.top.subtype()
    else
      category_ = "unknown"
    end if
  
    if type(data_) = "<uninitialized>" or data_ = invalid then
      ? " >>> ";category_;" # ";msg_
    else
      ? " >>> ";category_;" # ";msg_;" --- ";data_
    end if
  end sub