Required files
nokogiri/xml/sax
nokogiri/xml/before_handler
nokogiri/xml/after_handler
nokogiri/xml/node
nokogiri/xml/attr
nokogiri/xml/dtd
nokogiri/xml/text
nokogiri/xml/cdata
nokogiri/xml/processing_instruction
nokogiri/xml/comment
nokogiri/xml/document
nokogiri/xml/document_fragment
nokogiri/xml/node_set
nokogiri/xml/syntax_error
nokogiri/xml/xpath
nokogiri/xml/xpath_context
nokogiri/xml/builder
nokogiri/xml/reader
nokogiri/xml/notation
nokogiri/xml/element
nokogiri/xml/entity_declaration