code: def add_net16string(self, string):
  		
  		if len(string) >= (1 << 16):
  			raise ValueError("string too long")
  		return self.add_net16int(len(string)).add(string)
docs: >>> OutBuffer().add_net16string(b"x").getvalue() == b'\\x00\\x01x'
  		True
  
  		@type string: bytes
  		@param string: maximum length must fit in a 16bit integer
  		@returns: self
  		@raises OmapiSizeLimitError: