code: def fixture_prometheus():
      """fixture_prometheus"""
  
      offset = int(round(time.time() * 1000))
      args = "coredns_dns_request_count_total"
  
      def func(q):
          v = tfio.experimental.IODataset.from_prometheus(
              q, 5, offset=offset, endpoint="http://localhost:9090"
          )
          v = v.map(
              lambda timestamp, value: (
                  timestamp,
                  value["coredns"]["localhost:9153"][
                      "coredns_dns_request_count_total"
                  ],
              )
          )
          v = v.map(
              lambda timestamp, value: (
                  tf.stack(
                      [tf.cast(timestamp - offset, tf.float64), value]
                  )
              )
          )
          return v
  
      expected = [[np.float64(i), 6.0] for i in range(-5000, 0, 1000)]
  
      return args, func, expected
  
imports: import os
  import sys
  import time
  import shutil
  import tempfile
  import numpy
  import pytest
  import tensorflow
  import tensorflow_io
label_desc: Use image node_id 9 for calling a global function with example usage: fixture_prometheus() and returns: args,  func,  expected, v