code: def _merge_vocabulary(*vocabularies):
      vocabulary = {
          key: i
          for i, key in enumerate(
              sorted(set(itertools.chain.from_iterable(vocabularies)))
          )
      }
      return vocabulary
  
imports: import itertools
  import dask
  import dask.array
  import dask.bag
  import dask.dataframe
  import distributed
  import numpy
  import scipy.sparse
  import sklearn.base
  import sklearn.feature_extraction.text
  from dask.delayed import Delayed
  from distributed import get_client, wait
  from sklearn.utils.validation import check_is_fitted
label_desc: Use image node_id 5 for calling a global function with example usage: _merge_vocabulary() and returns: vocabulary