langchain/callbacks/tracers/langchain.py/LangChainTracer/ensure_tenant_id
class LangChainTracer:    def ensure_tenant_id(self) -> str:
        """Load or use the tenant ID."""
        tenant_id = self.tenant_id or _get_tenant_id(
            self.tenant_id, self._endpoint, self._headers
        )
        self.tenant_id = tenant_id
        return tenant_id