class REXML::Document

def self.entity_expansion_limit= val
  @@entity_expansion_limit = val
end

def record_entity_expansion!
  @number_of_expansions ||= 0
  @number_of_expansions += 1
  if @number_of_expansions > @@entity_expansion_limit
    raise "Number of entity expansions exceeded, processing aborted."
  end
end