       self = @
       method data_last, send
       self = null
-      ### somewhat hidden in the docs: *must* call `@queue null` to end stream: ###
-      # defer -> @queue null
-      @queue null
+      # defer -> @queue PS.symbols.end
+      @queue PS.symbols.end
       return null
   #.........................................................................................................
   return pull_through on_data, on_end

  has_ended   = false
  #.........................................................................................................
  pipeline.push @$surround settings if settings._surround
  pipeline.push @$surround { last: symbols.last, }
  #.........................................................................................................
  pipeline.push $paramap ( d, handler ) =>
    collector   = []
    #.......................................................................................................
    send = ( d ) =>
      return handler true if d is null
      collector.unshift d
      return null
    #.......................................................................................................

#-----------------------------------------------------------------------------------------------------------
@_get_remit_settings = ( hint, method ) ->
  defaults  =
    first:    @symbols.misfit
    last:     @symbols.misfit
    between:  @symbols.misfit
    after:    @symbols.misfit
    before:   @symbols.misfit
  settings  = assign {}, defaults
  switch arity = arguments.length
    when 1
