def handle_source_change(change, filename)
      @aggregators.each { |agg| agg.source_change(change, File.expand_path(filename, Dir.pwd)) }
    end
def handle_source_change(change, filename)
      @aggregators.each { |agg| agg.source_change(change, File.expand_path(filename, Dir.pwd)) }
    end
Source change handler