class PDF::Reader::TextRun

def character_count
  if @text.size == 1
    1.0
  elsif @text.respond_to?(:bytesize)
    # M17N aware VM
    # so we can trust String#size to return a character count
    @text.size.to_f
  else
    text.unpack("U*").size.to_f
  end
end