# File lib/brakeman/processors/alias_processor.rb, line 916
  def only_ivars include_request_vars = false, lenv = nil
    lenv ||= env
    res = SexpProcessor::Environment.new

    if include_request_vars
      lenv.all.each do |k, v|
        #TODO Why would this have nil values?
        if (k.node_type == :ivar or request_value? k) and not v.nil?
          res[k] = v.dup
        end
      end
    else
      lenv.all.each do |k, v|
        #TODO Why would this have nil values?
        if k.node_type == :ivar and not v.nil?
          res[k] = v.dup
        end
      end
    end

    res
  end