code: private boolean isSchemaLocationAttributeForKnownNamespaceUri(final Attr attribute) {
  
          final Element parent = attribute.getOwnerElement();
  
          // <xs:import namespace="http://yet/another/namespace" schemaLocation="schema1.xsd"/>
          return XMLConstants.W3C_XML_SCHEMA_NS_URI.equals(parent.getNamespaceURI())
                  && IMPORT.equalsIgnoreCase(parent.getLocalName())
                  && namespaceUriToNewFilenameMap.containsKey(getNamespace(attribute))
                  && SCHEMA_LOCATION.equals(attribute.getName());
      }
docs: Discovers if the provided attribute is a schemaLocation definition, which should
  be changed by this ChangeFilenameProcessor. Such an attribute is on the form
  <code>&lt;xs:import namespace="http://a/registered/namespace" schemaLocation="schema1.xsd"/&gt;</code>.
  
  @param attribute the attribute to test.
  @return <code>true</code> if the provided attribute is a schemaLocation definition
  whose namespace is known to this ChangeFilenameProcessor.