@Override
    public String toString() {
        return "Endpoint(" +
            "listenerName='" + listenerName + '\'' +
            ", securityProtocol=" + securityProtocol +
            ", host='" + host + '\'' +
            ", port=" + port +
            ')';
    }
Returns the port to which the listener is bound.
clients/src/main/java/org/apache/kafka/common/Endpoint.java