Required files
thread
open-uri
transaction/simple
color
pdf/math
pdf/writer/lang
pdf/writer/lang/en
zlib
pdf/writer/arc4
pdf/writer/fontmetrics
pdf/writer/object
pdf/writer/object/action
pdf/writer/object/annotation
pdf/writer/object/catalog
pdf/writer/object/contents
pdf/writer/object/destination
pdf/writer/object/encryption
pdf/writer/object/font
pdf/writer/object/fontdescriptor
pdf/writer/object/fontencoding
pdf/writer/object/image
pdf/writer/object/info
pdf/writer/object/outlines
pdf/writer/object/outline
pdf/writer/object/page
pdf/writer/object/pages
pdf/writer/object/procset
pdf/writer/object/viewerpreferences
pdf/writer/ohash
pdf/writer/strokestyle
pdf/writer/graphics
pdf/writer/graphics/imageinfo
pdf/writer/state
rexml/document