driver-core/src/main/com/mongodb/operation/AggregateToCollectionOperation.java
public ReadOperation<BsonDocument> asExplainableOperation(final ExplainVerbosity explainVerbosity) {
        return new AggregateExplainOperation(namespace, pipeline)
                .allowDiskUse(allowDiskUse)
                .maxTime(maxTimeMS, TimeUnit.MILLISECONDS)
                .hint(hint);
    }
public ReadOperation<BsonDocument> asExplainableOperation(final ExplainVerbosity explainVerbosity) {
        return new AggregateExplainOperation(namespace, pipeline)
                .allowDiskUse(allowDiskUse)
                .maxTime(maxTimeMS, TimeUnit.MILLISECONDS)
                .hint(hint);
    }
Gets an operation whose execution explains this operation.

@param explainVerbosity the explain verbosity
@return a read operation that when executed will explain this operation