code: def serialize(regularizer):
      return serialize_keras_object(regularizer)
  
imports: import math
  from tensorflow.python.keras import backend
  from tensorflow.python.keras.utils.generic_utils import deserialize_keras_object
  from tensorflow.python.keras.utils.generic_utils import serialize_keras_object
  from tensorflow.python.ops import math_ops
label_desc: Use image node_id 4 for calling a global function with example usage: serialize(regularizer) and returns: serialize_keras_object