memory

$canvaseditor memory: returns private memory
$canvaseditor memory key val …: set memory key to value
$canvaseditor memory key: returns value

obj method canvaseditor memory args {
  if {[llength $args] == 0} then {
    my memory
  } elseif {[llength $args] > 1} then {
    my memory {*}$args
  } else {
    dict get [my memory] {*}$args
  }
}