code: def allreduce(
      value,
      name=None,
      average=True,
      prescale_factor=1.0,
      postscale_factor=1.0,
      op=None,
      compression=Compression.none,
  ):
      """
      Perform an allreduce on a tensor-compatible value.
  
      Arguments:
          value: A tensor-compatible value to reduce.
                 The shape of the input must be identical across all ranks.
          name: Optional name for the constants created by this operation.
          average: If True, computes the average over all ranks.
                   Otherwise, computes the sum over all ranks.
          prescale_factor: Multiplicative factor to scale tensor before allreduce.
          postscale_factor: Multiplicative factor to scale tensor after allreduce.
          op: The reduction operation to combine tensors across different ranks.
          compression: Gradient compression algorithm to be used during allreduce.
                       Defaults to Compression.none.
      """
      return _impl.allreduce(
          K,
          value,
          name,
          average,
          prescale_factor,
          postscale_factor,
          op,
          compression,
      )
  
imports: import warnings
  from packaging import version
  import keras
  import keras.backend
  import tensorflow
  from horovod.tensorflow import init
  from horovod.tensorflow import shutdown
  from horovod.tensorflow import size, local_size, cross_size, rank, local_rank, cross_rank
  from horovod.tensorflow import is_initialized, start_timeline, stop_timeline
  from horovod.tensorflow import mpi_threads_supported, mpi_enabled, mpi_built
  from horovod.tensorflow import gloo_enabled, gloo_built
  from horovod.tensorflow import nccl_built, ddl_built, ccl_built, cuda_built, rocm_built
  from horovod.tensorflow import Average, Sum, Adasum
  from horovod.tensorflow.compression import Compression
  from horovod.tensorflow.mpi_ops import global_process_set
  from horovod.keras import callbacks, elastic
  import horovod._keras
label_desc: Use image node_id 4 for calling a global function with example usage: allreduce(value, name, average, prescale_factor, postscale_factor, op, compression) and returns: _impl