\Astart of string
*matches any number of characters from the set below:
\sany whitespace character
\Sany non-whitespace character
\Sany non-whitespace character
\Kresets the starting point of the reported match. Any previously consumed characters are no longer included in the final match
\s*any whitespace character, repeated any number of times
\zend of string
g modifier: global. Finds all matches instead of stopping after the first