Remove gauge metric

Hi all,
I have written a custom exporter for calculating the cost of using a node in AWS.
Here is how it works:
Lets assume I have 3 nodes, each costs 5$/ 1h, when I plot using grafana the sum(cost_metric{}) i get 15$ (3x5$). Lets say after 2 hours one of the nodes get deleted (autoscaling). In that case the total cost should drop to 10$.

The problem is that in my case the metric is preserved and even though the node has been deleted the cost is kept and thus it displays 15$ instead of dropping to 10$

How would I go about saving that problem?

cost_metric = Gauge(
    "cost_metric ",
    "Cost of running an instance for 1 hour",
    ["node_name", "instance_type"],
)
...

node_names = get_nodes()
    for node_name in node_names:
        node_info = get_node_info(node_name)
        if node_info is None:
            continue

        logging.info(f"Updating metrics for node: {node_name}")

        # labels section
        labels = node_info["metadata"]["labels"]
        instance_type = labels.get("beta.kubernetes.io/instance-type", "unknown")
        cost = get_cost_of_instance(instance_type)

        if cost is not None:
            cost_metric.labels(node_name=node_name, instance_type=instance_type).set(cost)

I tried

I collected previous and current nodes in form of dict and then wanted to removed the ones that arent existing, the issue is that :

cost_metric.remove(node_name=node_name, instance_type=instance_type)

Traceback (most recent call last):
  File "/home/XXXX/projects/main.py", line 154, in <module>
    previous_nodes = update_metrics(previous_nodes)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/eksohio/projects/main.py", line 131, in update_metrics
    cost.remove(node_name=node_name, instance_type=instance_type)
TypeError: MetricWrapperBase.remove() got an unexpected keyword argument 'node_name'

The payload names the Gauge declaration and the MetricWrapperBase.remove call in the traceback, but no repository file or test. Start by checking the Gauge and MetricWrapperBase APIs for label removal and review the exporter loop shown. Done means establishing the supported way to remove the deleted node's metric or confirming that a library change is needed.