presto-main/src/main/java/io/prestosql/memory/MemoryPool.java/MemoryPool/toString
class MemoryPool:    @Override
    public synchronized String toString()
    {
        return toStringHelper(this)
                .add("id", id)
                .add("maxBytes", maxBytes)
                .add("freeBytes", getFreeBytes())
                .add("reservedBytes", reservedBytes)
                .add("reservedRevocableBytes", reservedRevocableBytes)
                .add("future", future)
                .toString();
    }