DLMS Client for python

Hello! I have a problem with understanding readme.md file in dlms python github repository. Here i found that part of code:
reply = GXReplyData()
data = self.client.snrmRequest()
if data:
self.readDLMSPacket(data, reply)
self.client.parseUAResponse(reply.data)
size = self.client.limits.maxInfoTX + 40
self.replyBuff = bytearray(size)
reply.clear()
self.readDataBlock(self.client.aarqRequest(), reply)
self.client.parseAareResponse(reply.data)
reply.clear()
if self.client.authentication.value > Authentication.LOW.value:
for it in self.client.getApplicationAssociationRequest():
self.readDLMSPacket(it, reply)
self.client.parseApplicationAssociationResponse(reply.data)

I don't understand how i can use it. To which class self parameter is related here? And I need only these lines of code to connect to the meter ?