XML patterns
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- `attributes` matches attributes without their values
- `attributes_and_values` matches attributes and values
- `comments` matches comments
- `elements` matches element tags without their values
- `pis` matches processing instructions
- `tags` matches tag names (element and attribute tags)
- `zap_comments` removes comments from matches
- `zap_pis` removes processing instructions from matches
- `zap_strings` removes attribute string values from matches
