class_docstr: Apache Beam accumulator to compute the mean/stdev of svg commands.
class_docstr_tok: ["Apache","Beam","accumulator","to","compute","the","mean\/stdev","of","svg","commands","."]
code: def merge_accumulators(self, accumulators):
      curr_sums, sum_sqs, counts = list(zip(*accumulators))
      return (
          np.sum(curr_sums, axis=0),
          np.sum(sum_sqs, axis=0),
          np.sum(counts),
      )
  
imports: from absl import app
  from absl import flags
  import apache_beam
  from magenta.models.svg_vae import svg_utils
  import numpy
  from tensor2tensor.data_generators import generator_utils
  import tensorflow.compat.v1
label_desc: Use image node_id 3 for calling the MeanStddev obj's underlying member method code with example usage: obj.merge_accumulators(accumulators) and returns: np,  np,  np