private static String readNameFromJson( String jsonPath ) throws IOException {
		try( Reader reader = new InputStreamReader( new FileInputStream( jsonPath ), StandardCharsets.UTF_8 ) ) {
			@SuppressWarnings( "unchecked" )
			Map<String, Object> json = (Map<String, Object>) Json.parse( reader );
			return (String) json.get( "name" );
		} catch( ParseException ex ) {
			throw new IOException( ex.getMessage(), ex );
		}
	}
This tool checks whether there are duplicate name fields in all theme .json files.

This is important for following file, where the name is used for theme specific UI defaults:
  flatlaf-core/src/main/resources/com/formdev/flatlaf/IntelliJTheme$ThemeLaf.properties

@author Karl Tauber
flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/intellijthemes/IJThemesDuplicateNameChecker.java