driver-core/src/main/com/mongodb/operation/CountOperation.java
public AsyncReadOperation<BsonDocument> asExplainableOperationAsync(final ExplainVerbosity explainVerbosity) {
        if (countStrategy.equals(CountStrategy.COMMAND)) {
            return createExplainableOperation(explainVerbosity);
        } else {
            return getAggregateOperation().asExplainableOperationAsync(explainVerbosity);
        }
    }
public AsyncReadOperation<BsonDocument> asExplainableOperationAsync(final ExplainVerbosity explainVerbosity) {
        if (countStrategy.equals(CountStrategy.COMMAND)) {
            return createExplainableOperation(explainVerbosity);
        } else {
            return getAggregateOperation().asExplainableOperationAsync(explainVerbosity);
        }
    }
Gets an operation whose execution explains this operation.

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