code: def execute_to_legacy_block_iterator(
      executor: Executor,
      plan: ExecutionPlan,
      allow_clear_input_blocks: bool,
      dataset_uuid: str,
  ) -> Iterator[Tuple[ObjectRef[Block], BlockMetadata]]:
      """Same as execute_to_legacy_bundle_iterator but returning blocks and metadata."""
      bundle_iter = execute_to_legacy_bundle_iterator(
          executor, plan, allow_clear_input_blocks, dataset_uuid
      )
      for bundle in bundle_iter:
          for block, metadata in bundle.blocks:
              yield block, metadata
  
imports: from typing import Iterator, Tuple
  from ray.data._internal.block_list import BlockList
  from ray.data._internal.execution.interfaces import Executor, PhysicalOperator, RefBundle
  from ray.data._internal.lazy_block_list import LazyBlockList
  from ray.data._internal.logical.interfaces.logical_plan import LogicalPlan
  from ray.data._internal.logical.operators.read_operator import Read
  from ray.data._internal.logical.optimizers import get_execution_plan
  from ray.data._internal.logical.rules.set_read_parallelism import compute_additional_split_factor
  from ray.data._internal.logical.util import record_operators_usage
  from ray.data._internal.plan import ExecutionPlan
  from ray.data._internal.planner.plan_read_op import apply_output_blocks_handling_to_read_task
  from ray.data._internal.stats import DatasetStats
  from ray.data.block import Block, BlockMetadata, List
  from ray.data.context import DataContext
  from ray.types import ObjectRef
label_desc: Use image node_id 1 for calling a global function with example usage: execute_to_legacy_block_iterator(executor, plan, allow_clear_input_blocks, dataset_uuid) without return types