code: def dot(x, y, sparse=False):
      """Wrapper for tf.matmul (sparse vs dense)."""
      if sparse:
          res = tf.sparse_tensor_dense_matmul(x, y)
      else:
          res = tf.matmul(x, y)
      return res
  
imports: from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  from .models_base import glorot
  from .models_base import Model
  import tensorflow
label_desc: Use image node_id 3 for calling a global function with example usage: dot(x, y, sparse) and returns: res