docstr: Tests that the method for obtaining PR curve data raises a
  ValueError.
  
  The handler should raise a ValueError when no PR curve data can
  be found for a certain run-tag combination.
docstr_tok: ["Tests","that","the","method","for","obtaining","PR","curve","data","raises","a","ValueError",".","The","handler","should","raise","a","ValueError","when","no","PR","curve","data","can","be","found","for","a","certain","run-tag","combination","."]
code: def testPrCurvesRaisesValueErrorWhenNoData(self):
      """Tests that the method for obtaining PR curve data raises a
      ValueError.
  
      The handler should raise a ValueError when no PR curve data can
      be found for a certain run-tag combination.
      """
      with self.assertRaisesRegex(
          ValueError, r"No PR curves could be found"
      ):
          self.plugin.pr_curves_impl(
              context.RequestContext(),
              "123",
              ["colors"],
              "non_existent_tag",
          )
  
      with self.assertRaisesRegex(
          ValueError, r"No PR curves could be found"
      ):
          self.plugin.pr_curves_impl(
              context.RequestContext(),
              "123",
              ["non_existent_run"],
              "blue/pr_curves",
          )
  
imports: import collections.abc
  import functools
  import os.path
  import numpy
  import tensorflow
  from tensorboard import context
  from tensorboard.backend.event_processing import plugin_event_multiplexer
  from tensorboard.backend.event_processing import data_provider
  from tensorboard.plugins import base_plugin
  from tensorboard.plugins.pr_curve import pr_curve_demo
  from tensorboard.plugins.pr_curve import pr_curves_plugin
label_desc: Use image node_id 7 for calling the PrCurvesPluginTest obj's underlying member method code with example usage: obj.testPrCurvesRaisesValueErrorWhenNoData() without return types