some XMIR elements must have content in order to be present

See #3549, release log:

• 1a9e532 by @yegor256: Merge pull request #3550 from ...
• 6f11b2c by @yegor256: #3549: simplified
• 3d9a74d by @yegor256: #3549: doc
• 0a47bce by @yegor256: #3549: tests fixed
• beabd79 by @yegor256: #3549: test
• 500b50e by @yegor256: #3549: typo
• 7252aad by @yegor256: #3549: better logging
• cde4802 by @yegor256: #3549: doc
• 44bf11a by @yegor256: #3549: avoid errors if not lin...
• c28343f by @yegor256: #3549: parser clean
• 42d8efb by @yegor256: #3549: more fixes
• a75f8a3 by @yegor256: #3549: mostly fixed tests
• 424237c by @yegor256: #3549: stricter
• 772d440 by @yegor256: doc for XSD
• 181a8e1 by @yegor256: stricter XSD
• 7b05356 by @yegor256: Merge pull request #3548 from ...
• 943335b by @maxonfjvipon: fix(#3529): checkstyle
• 60bb0cd by @maxonfjvipon: fix(#3529): macos 13
• 9b86bc4 by @maxonfjvipon: fix(#3529): snippet with curre...
• 81a5f6c by @maxonfjvipon: fix(#3529): utf8
• and 23 more...

Released by Rultor 2.0-SNAPSHOT, see build log