Answer: DirectPipelineRunner

The `DirectPipelineRunner` class is designed for executing pipeline operations directly, bypassing any optimization steps. This makes it particularly suitable for small-scale local executions and testing scenarios. For more details, refer to the [Google Cloud Dataflow Java SDK documentation](https://cloud.google.com/dataflow/java-sdk/JavaDoc/com/google/cloud/dataflow/sdk/runners/DirectPipelineRunner).

Author: LeetQuiz Editorial Team