from typing import List
import yaml


def assemble_container_names(validated_compose_content: str) -> List[str]:
    """returns the list of container names from a validated compose_spec"""
    parsed_compose_spec = yaml.safe_load(validated_compose_content)
    return [
        service_data["container_name"]
        for service_data in parsed_compose_spec["services"].values()
    ]