code: def _reference(preds, target, reduce=False):
      """Reference implementation of `CLIPImageQualityAssessment` metric."""
      res = piq.CLIPIQA()(preds).squeeze()
      return res.sum() if reduce else res
  
imports: import os
  from functools import partial
  import matplotlib
  import matplotlib.pyplot
  import piq
  import pytest
  import torch
  from PIL import Image
  from torch import Tensor
  from torchmetrics.functional.multimodal.clip_iqa import clip_image_quality_assessment
  from torchmetrics.multimodal.clip_iqa import CLIPImageQualityAssessment
  from torchmetrics.utilities.imports import _PIQ_GREATER_EQUAL_0_8, _TRANSFORMERS_GREATER_EQUAL_4_10
  from torchvision.transforms import PILToTensor
  from unittests.helpers.testers import MetricTester
  from unittests.image import _SAMPLE_IMAGE
  from unittests.text.helpers import skip_on_connection_issues
label_desc: Use image node_id 3 for calling a global function with example usage: _reference(preds, target, reduce) and returns: unknown