code: def on_fit_start(self) -> None:
      self.build_guidance(self.guidance_cfg)
      self.prepare_embeddings()
  
file_path: NeMo/nemo/collections/multimodal/models/nerf/txt2nerf_base.py
imports: from nemo.collections.multimodal.models.nerf.base import NerfModelBase
label_desc: Use image node_id 5 for calling the Txt2NerfBase obj's underlying member method code with example usage: obj.on_fit_start() without return types