code: def get_model_path(custom_model, default_model_path):
      """Determine the model path based on the existence of the custom model.
  
      Args:
          custom_model: The path to the custom model provided by the user.
          default_model_path: The path to the default model.
  
      Returns:
          The path to the model to be used.
      """
      if custom_model is not None and os.path.exists(custom_model):
          print(f"Using provided model: {custom_model}")
          return custom_model
      else:
          if custom_model is not None:
              print(
                  f"Warning: Provided model '{custom_model}' not found. "
                  "Using default model instead."
              )
          print(f"Using default model: {default_model_path}")
          return default_model_path
  
imports: import os
  import numpy
label_desc: Use image node_id 4 for calling a global function with example usage: get_model_path(custom_model, default_model_path) and returns: custom_model, default_model_path