class_docstr: Cell for Sequential User Matrix
class_docstr_tok: ["Cell","for","Sequential","User","Matrix"]
code: def state_size(self):
      return self._num_units
  
imports: import numpy
  import tensorflow
  from keras.layers.legacy_rnn.rnn_cell_impl import LayerRNNCell
  from tensorflow.python.eager import context
  from tensorflow.python.keras import activations
  from tensorflow.python.keras import initializers
  from tensorflow.python.keras.utils import tf_utils
  from tensorflow.python.ops import math_ops
  from tensorflow.python.platform import tf_logging
  from tensorflow.python.ops import init_ops
  from tensorflow.python.framework import dtypes
  from tensorflow.python.util import nest
label_desc: Use image node_id 2 for calling the SUMCell obj's underlying member method code with example usage: obj.state_size() and returns: self