class PDF::Reader::LZW

def self.create_new_string(string_table, some_code, other_code)
  raise MalformedPDFError, "invalid LZW data" if some_code.nil? || other_code.nil?
  item_one = string_table[some_code]
  item_two = string_table[other_code]
  if item_one && item_two
    item_one + item_two.chr
  else
    raise MalformedPDFError, "invalid LZW data"
  end
end