class_docstr: Monitor Simple Moving Average (SMA), i.e. an average within a sliding window,
  of some tensors.
class_docstr_tok: ["Monitor","Simple","Moving","Average","(","SMA",")",",","i.e",".","an","average","within","a","sliding","window",",","of","some","tensors","."]
code: def _setup_graph(self):
      tensors = self.get_tensors_maybe_in_tower(self._tensor_names)
      for t in tensors:
          assert (
              t.get_shape().ndims == 0
          ), "SimpleMovingAverage only accepts scalar tensor! Got one with {}".format(
              t.get_shape()
          )
      self._fetch = tf.train.SessionRunArgs(fetches=tensors)
  
imports: import numpy
  from collections import deque
  from ..compat import tfv1
  from ..tfutils.common import get_op_tensor_name
  from ..utils import logger
  from ..utils.naming import MOVING_SUMMARY_OPS_KEY
  from .base import Callback
label_desc: Use image node_id 2 for calling the SimpleMovingAverage obj's underlying member method code with example usage: obj._setup_graph() without return types