Can't add connection to pool

Hi Georg,

I created a pool with only 2 pre connections with

import mariadb

conn_parameter = {'host': .... }

pool = mariadb.ConnectionPool(pool_name='test', pool_size=2, **conn_parameter)

Checked the max_size of pool

print(pool.max_size)

# Returned 64

But, if I try to add some new connection to pool,

new_db = mariadb.connect(**conn_parameter)

pool.add_connection(new_db)

I get the exception mariadb.PoolError: Couldn't add connection to pool 'test' (no free slot available).

Am I missing something?