code: def instance_norm(x, epsilon=1e-8):
      assert len(x.shape) == 4  # NCHW
      with tf.variable_scope("InstanceNorm"):
          orig_dtype = x.dtype
          x = tf.cast(x, tf.float32)
          x -= tf.reduce_mean(x, axis=[2, 3], keepdims=True)
          epsilon = tf.constant(epsilon, dtype=x.dtype, name="epsilon")
          x *= tf.rsqrt(
              tf.reduce_mean(tf.square(x), axis=[2, 3], keepdims=True)
              + epsilon
          )
          x = tf.cast(x, orig_dtype)
          return x
  
imports: import numpy
  import tensorflow
  import dnnlib
  import dnnlib.tflib
label_desc: Use image node_id 15 for calling a global function with example usage: instance_norm(x, epsilon) and returns: x