class String

  String self.new_string(int len )
    len =  len << 2
    return super.new_object( len)
  end

  int length()
    return self.length
  end

  int plus(String str)
    my_length = self.length
    str_len = str.length()
    my_length = str_len + my_length
    new_string = self.new_string(my_length )
    i = 0
    while_plus( i - my_length)
      char = get(i)
      new_string.set(i , char)
      i = i + 1
    end
    i = 0
    while_plus( i - str_len)
      char = str.get(i)
      len = i + my_length
      new_string.set(  len , char)
      i = i + 1
    end
    return new_string
  end

end
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