code: def to_tensor(self):
      
      a_shape = shape_list(self.a)
      b_shape = shape_list(self.b)
      inner_dim = b_shape[1]
      result_dim = b_shape[0]
      flat_a = tf.reshape(self.a, [-1, inner_dim])
      product = tf.matmul(flat_a, self.b, transpose_b=True)
      product_shape = a_shape[:-1] + [result_dim]
      product = tf.reshape(product, product_shape)
      product.set_shape(self.a.get_shape().as_list()[:-1] +
                        [self.b.get_shape()[0]])
      return product
docs: Convert to Tensor.