# File lib/ruby_parser_extras.rb, line 141
  def clean_mlhs sexp
    case sexp.sexp_type
    when :masgn then
      if sexp.size == 2 and sexp[1].sexp_type == :array then
        s(:masgn, *sexp[1][1..-1].map { |sub| clean_mlhs sub })
      else
        sexp
      end
    when :gasgn, :iasgn, :lasgn, :cvasgn then
      if sexp.size == 2 then
        sexp.last
      else
        sexp # optional value
      end
    else
      raise "unsupported type: #{sexp.inspect}"
    end
  end