Cannot integrate Prometheus with Opentelemetry

Opentelemetry official documentation (https://open-telemetry.github.io/opentelemetry-python/exporter/prometheus/prometheus.html) has used the following packages to integrate Prometheus

1. PrometheusMetricsExporter
2. PushController

However, these classes are not visible. IDE that I used for this is Pycharm. I used the following statement to import libraries.

from opentelemetry.exporter.prometheus import PrometheusMetricsExporter
from opentelemetry.sdk.metrics.export.controller import PushController