human
Solve the following python programming problem given the following code:
def blockchain_connect(self) : 
    '
    If your Oracle is in test mode, then blockchain server is different than default server
    ' 
    def server_connection() : 
        if TEST_MODE : 
            self.blockchain_server = jsonrpclib.Server ('http://{0}:{1}@{2}:{3}'.format (BITCOIND_TEST_RPC_USERNAME, BITCOIND_TEST_RPC_PASSWORD, BITCOIND_TEST_RPC_HOST, BITCOIND_TEST_RPC_PORT)) 
else : 
            self.blockchain_server = jsonrpclib.Server ('http://{0}:{1}@{2}:{3}'.format (BITCOIND_RPC_USERNAME, BITCOIND_RPC_PASSWORD, BITCOIND_RPC_HOST, BITCOIND_RPC_PORT)) 
socket.setdefaulttimeout (None) 
        self.server.help () 
self._connect (self) 

    
    

    Fix the buggy line: self._connect (self)
assistant
#Here is Python program to fix the buggy line: self.

self._connect (def server_connection()