class_docstr: Base density estimator.
docstr: Compose model using collected features.
code: def fit(self):
      """Compose model using collected features."""
      raise NotImplementedError
  
imports: from __future__ import annotations
  from abc import ABC, abstractmethod
  from typing import Any
  import torch
  from sklearn.mixture import GaussianMixture
  from torch import Tensor, nn
  from anomalib.models.ai_vad.features import FeatureType
  from anomalib.utils.metrics.min_max import MinMax
label_desc: Use image node_id 3 for calling the BaseDensityEstimator obj's underlying member method code with example usage: obj.fit() without return types