combine_pdf.rb in combine_pdf-0.2.7

- old
+ new

@@ -2,9 +2,10 @@
 
 require 'zlib'
 require 'securerandom'
 require 'strscan'
 require 'matrix'
+require 'set'
 
 #require the RC4 Gem
 require 'rc4'
 
 