private void doSnapshot(final Closure done, boolean sync) {
        if (this.snapshotExecutor != null) {
            if (sync) {
                this.snapshotExecutor.doSnapshotSync(done);
            } else {
                this.snapshotExecutor.doSnapshot(done);
            }
        } else {
            if (done != null) {
                final Status status = new Status(RaftError.EINVAL, "Snapshot is not supported");
                ThreadPoolsFactory.runClosureInThread(this.groupId, done, status);
            }
        }
    }
Retrieve current configuration this node seen so far. It's not a reliable way to
retrieve cluster peers info, you should use {@link #listPeers()} instead.

@return current configuration.

@since 1.0.3
jraft-core/src/main/java/com/alipay/sofa/jraft/core/NodeImpl.java