code: def blur2d(x, f=[1, 2, 1], normalize=True):
      with tf.variable_scope("Blur2D"):
  
          @tf.custom_gradient
          def func(x):
              y = _blur2d(x, f, normalize)
  
              @tf.custom_gradient
              def grad(dy):
                  dx = _blur2d(dy, f, normalize, flip=True)
                  return dx, lambda ddx: _blur2d(ddx, f, normalize)
  
              return y, grad
  
          return func(x)
  
imports: import numpy
  import tensorflow
  import dnnlib
  import dnnlib.tflib
label_desc: Use image node_id 4 for calling a global function with example usage: blur2d(x, f, normalize) and returns: func, y,  grad, dx,  function