tools/metrics/histograms/test_data/histograms.xml

<histogram-configuration>

  <!-- Second level Comment 1 -->

<histograms>

<variants name="TestToken">
  <variant name="Variant1" summary="Label1"/>
  <variant name="Variant2" summary="Label2"/>
</variants>

<histogram name="Foo.Bar" units="xxxxxxxxxxxxxxxxxxyyyyyyyyyyyyyyyyyyyyyyzzzz"
    expires_after="M85">
  <summary>Foo</summary>
  <owner>person@chromium.org</owner>
  <component>Component</component>
</histogram>

<histogram name="Test.TokenHistogram{TestToken}" units="microseconds"
    expires_after="M85">
  <obsolete>
    Removed 6/2020.
  </obsolete>
  <owner>person@chromium.org</owner>
  <summary>
    Summary 2
  </summary>
  <token key="TestToken" variants="TestToken"/>
</histogram>

<histogram name="Test.Histogram" units="microseconds" expires_after="M85">
  <obsolete>
    Removed 6/2020.
  </obsolete>
  <owner>person@chromium.org</owner>
  <summary>
    Summary 2
  </summary>
</histogram>

<histogram name="Test.EnumHistogram" enum="TestEnum" expires_after="M81">
  <owner>uma@chromium.org</owner>
  <obsolete>
    Obsolete message
  </obsolete>
  <summary>
    A enum histogram.
  </summary>
</histogram>

</histograms>

<histogram_suffixes_list>

<histogram_suffixes name="Test.HistogramSuffixes" separator=".">
  <suffix name="TestSuffix" label="A histogram_suffixes"/>
  <affected-histogram name="Test.Histogram"/>
</histogram_suffixes>

</histogram_suffixes_list>

</histogram-configuration>