code: def exists(val):
      return val is not None
  
file_path: lambda-networks/lambda_networks/tfkeras.py
imports: import tensorflow
  from einops.layers.tensorflow import Rearrange
  from tensorflow.keras.layers import Conv2D, BatchNormalization, Conv3D, ZeroPadding3D, Softmax, Lambda, Add, Layer
  from tensorflow.keras import initializers
  from tensorflow import einsum, nn, meshgrid
label_desc: Use image node_id 1 for calling a global function with example usage: exists(val) and returns: unknown