removeEmptyContainers

Remove container elements in the document that have no children or meaningful attributes, excluding the <svg> element which is ignored.

A container, as defined in the SVG specifications, is an SVG element that can have graphical child elements. Container elements include:

• <a>
• <defs>
• <glyph>
• <g>
• <marker>
• <mask>
• <missing-glyph>
• <pattern>
• <svg>
• <switch>
• <symbol>