diff --git a/.gitattributes b/.gitattributes
new file mode 100644
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+++ b/.gitattributes
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+# Captured golden data. GitHub collapses generated files in pull request diffs.
+hscontrol/policy/v2/testdata/*_results/** linguist-generated
+hscontrol/servertest/testdata/steps/** linguist-generated
+hscontrol/testdata/apiv1_golden/** linguist-generated