code: def insert_in_background_intensity(
      metadata: Dict[str, Any], **kwargs
  ) -> float:
      bg_to_src_duration_ratio = (
          metadata["dst_duration"] - metadata["src_duration"]
      ) / metadata["dst_duration"]
      return bg_to_src_duration_ratio * 100.0
  
imports: from typing import Any, Callable, Dict, Optional, Tuple
  import numpy
label_desc: Use image node_id 8 for calling a global function with example usage: insert_in_background_intensity(metadata) and returns: unknown