def METHOD_NAME(self) -> Sequence[str]:
    """Get command sequence for `env` with configured flags."""
    env_list = ["env"]
    # Pass through configurable environment variables.
    for key in ["http_proxy", "https_proxy"]:
        value = self.build_provider_flags.get(key)
        if not value:
            continue
        # Ensure item is treated as string and append it.
        value = str(value)
        env_list.append(f"{key}={value}")
    return env_list