# File lib/rgen/fragment/model_fragment.rb, line 216
  def unresolve_external
    return if @resolved_refs.nil?
    raise "can not unresolve, missing fragment information" if @resolved_refs == :dirty || @resolved_refs[:unknown]
    rrefs = @resolved_refs.values.flatten
    @resolved_refs = {}
    unresolve_refs(rrefs)
  end