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 rank of this worker node.
  
  Returns
  -------
  rank : int
      The rank of this node, which is in range [0, num_workers())
docstr_tok: ["Returns","the","rank","of","this","worker","node",".","Returns","--","--","--","-","rank",":","int","The","rank","of","this","node",",","which","is","in","range","[","0",",","num_workers","(",")",")"]
code: def rank(self):
      """Returns the rank of this worker node.
  
      Returns
      -------
      rank : int
          The rank of this node, which is in range [0, num_workers())
      """
      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 8 for calling the KVStoreBase obj's underlying member method code with example usage: obj.rank() without return types