Restricting href to specific file extension



I was wandering if it’s possible to restrict href files to specific file types. For example only allow files with .css extension? I know how to do that check with a simple php function, but was wandering if that functionality is already present?

Was trying this earlier but it doesn’t seem to work:

this->href( ‘stylesheet’, [
‘types’ => [ ‘asset’ ], ‘subtypes’ => [ ‘asset’ => [ ‘file’, ‘*.css’ ] ]
] )