code: def get_available_backends():
      return list(backend_map.keys())
  
imports: import inspect
  import os
  from pathlib import Path
  from hls4ml.backends.template import Template
  from hls4ml.model.flow import get_backend_flows, update_flow
  from hls4ml.model.optimizer import LayerOptimizerPass, extract_optimizers_from_object, extract_optimizers_from_path, get_backend_passes, get_optimizer, register_pass
label_desc: Use image node_id 3 for calling a global function with example usage: get_available_backends() and returns: list