public String getErrorReport() {
		Map<String, List<PropertyMigration>> content = getContent(
				LegacyProperties::getUnsupported);
		if (content.isEmpty()) {
			return null;
		}
		StringBuilder report = new StringBuilder();
		report.append(String.format("%nThe use of configuration keys that are no longer "
				+ "supported was found in the environment:%n%n"));
		append(report, content);
		report.append(String.format("%n"));
		report.append("Please refer to the migration guide or reference guide for "
				+ "potential alternatives.");
		report.append(String.format("%n"));
		return report.toString();
	}
public String getErrorReport ( ) { Map < String , List < PropertyMigration > > content = getContent ( LegacyProperties :: getUnsupported ) ; if ( content . isEmpty ( ) ) { return null ; } StringBuilder report = new StringBuilder ( ) ; report . append ( String . format ( "%nThe use of configuration keys that are no longer " + "supported was found in the environment:%n%n" ) ) ; append ( report , content ) ; report . append ( String . format ( "%n" ) ) ; report . append ( "Please refer to the migration guide or reference guide for " + "potential alternatives." ) ; report . append ( String . format ( "%n" ) ) ; return report . toString ( ) ; }
Return a report for all the properties that are no longer supported. If no such
properties were found, return {@code null}.
@return a report with the configurations keys that are no longer supported