icon shows that the match occurred. The 
icon shows that there is no match or your expression contains a mistake. To verify that your regular expression is correct, place the caret within the expression you want to check, press &shortcut:ShowIntentionActions;, and select Edit RegExp.
In the popup, type a sample string that should match your regular expression. The icon shows that the match occurred. The icon shows that there is no match or your expression contains a mistake.
