class_docstr: An abstract key-value store interface for data parallel training.
class_docstr_tok: ["An","abstract","key-value","store","interface","for","data","parallel","training","."]
docstr: Returns the number of worker nodes.
  
  Returns
  -------
  size :int
      The number of worker nodes.
docstr_tok: ["Returns","the","number","of","worker","nodes",".","Returns","--","--","--","-","size",":","int","The","number","of","worker","nodes","."]
code: def num_workers(self):
      """Returns the number of worker nodes.
  
      Returns
      -------
      size :int
          The number of worker nodes.
      """
      raise NotImplementedError()
  
imports: from array import array
  import ctypes
  import warnings
  from ..ndarray import NDArray
  from ..base import _LIB, c_str_array, c_handle_array, c_array, c_array_buf, c_str
  from ..base import check_call, string_types
  from ..base import KVStoreHandle
  from ..profiler import set_kvstore_handle
label_desc: Use image node_id 9 for calling the KVStoreBase obj's underlying member method code with example usage: obj.num_workers() without return types