Test, validate and match regular expressions
Matches any line containing the whole word 'todo' followed later on the same line by the whole word 'jundan', both case-insensitively. This is ideal for IntelliJ's TODO tool window filter to show only TODO comments assigned to the developer 'jundan', e.g. '// TODO(jundan): fix this bug'. The global and multiline flags ensure every matching line in a file is found.