langchain/tools/steamship_image_generation/tool.py/SteamshipImageGenerationTool/validate_size
class SteamshipImageGenerationTool:    def validate_size(cls, values: Dict) -> Dict:
        if "size" in values:
            size = values["size"]
            model_name = values["model_name"]
            if size not in SUPPORTED_IMAGE_SIZES[model_name]:
                raise RuntimeError(f"size {size} is not supported by {model_name}")

        return values