papirus-icon-theme/Papirus/16x16/actions/window-maximize.svg

<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 16 16">
  <defs>
    <style type="text/css" id="current-color-scheme">
      .ColorScheme-Text {
        color:#5c616c;
      }
      </style>
  </defs>
  <path style="fill:currentColor;opacity:1" class="ColorScheme-Text" d="M 7 4 L 7 7 L 4 7 L 4 9 L 7 9 L 7 12 L 9 12 L 9 9 L 12 9 L 12 7 L 9 7 L 9 4 L 7 4 z "/>
</svg>