Exscript and Cisco

Question

I don’t understand why 3 connections are created when connecting to the switch and I can close only 1, there is not a word about this in the documentation.

account = Account(USER, PASSWORD)
conn = SSH2()
conn.connect(IP) 
conn.login(account) 
conn.execute('terminal length 0')
conn.execute('show users')
print(conn.response)
conn.send('exit')
conn.close()

Print:

show users
    Line       User       Host(s)              Idle       Location
   1 vty 0     user       idle                 00:00:05 10.3.0.251
   2 vty 1     user       idle                 00:00:04 10.3.0.251
*  3 vty 2     user       idle                 00:00:00 10.3.0.251