I removed one long bean definition for brevity, then source looks like below. When executed, I get: `Caused by: org.xml.sax.SAXParseException: cvc-elt.1: Cannot find the declaration of element 'constraint-mappings'.` Great, so there should be something wrong with schema or xml file.
But what. I never actually understood all that weird definition of namespaces. So first 3 http URLs leads nowhere and they probably serve some higher purpose, while the last one ending in xsd does exist and does define `constraint-mappings` element. And whole document is, according to Intellij IDEA valid, which it is I believe. I if I try to corrupt it, then IntellijIDEA sees it. So I'd presume that it actually is valid. So *why on earth* spring produces given error on startup???