private Deque<PoolableConnection> acquireDeque(String key) {
        requireNonNull(key);
        return pools.computeIfAbsent(key, unused -> new ConcurrentLinkedDeque<>());
    }
A fully concurrent implementation of a connection pool.

@author Per Minborg
runtime-parent/runtime-core/src/main/java/com/speedment/runtime/core/internal/component/ConnectionPoolComponentImpl.java