 
 class Builder extends Walker
 
-  constructor: ->
+  constructor: (ast, options={}, @source) ->
     super
     @_indent = 0
 

    new SourceNode(
      node.loc.start.line,
      node.loc.start.column,
      'input.js',
      output)

  ###

  ###

  onUnknownNode: (node, ctx) ->
    err = buildError({
      lineNumber: node.loc.start.line,
      column: node.loc.start.column,
      description: "#{ctx?.type} is not supported"
    }, @source, @options.filename)
    throw err

  ###
  # visitors:
