class_docstr: A blocking operator that executes once its inputs are complete.
  
  This operator implements distributed sort / shuffle operations, etc.
code: def _get_next_inner(self) -> RefBundle:
      return self._output_buffer.pop(0)
  
imports: from typing import List, Optional
  from ray.data._internal.execution.interfaces import AllToAllTransformFn, PhysicalOperator, RefBundle, TaskContext
  from ray.data._internal.logical.interfaces import LogicalOperator
  from ray.data._internal.progress_bar import ProgressBar
  from ray.data._internal.stats import StatsDict
label_desc: Use image node_id 6 for calling the AllToAllOperator obj's underlying member method code with example usage: obj._get_next_inner() and returns: self