code: def get_supported_onnx_layers():
      return list(layer_handlers.keys())
  
imports: import numpy
  import onnx
  from onnx import helper, numpy_helper, shape_inference
  from hls4ml.model import ModelGraph
label_desc: Use image node_id 8 for calling a global function with example usage: get_supported_onnx_layers() and returns: list