{{ $implicitSvg := .Get 0 }}
{{ $svg := .Get "svg" | default $implicitSvg }}
{{ $implicitClass := .Get 1 | default "" }}
{{ $class := .Get "class" | default $implicitClass }}
{{ $svgCode := $svg | readFile }}

{{ $scratch := newScratch }}
{{ $scratch.Set "svgOutput" $svgCode }}

{{ if ne $class "" }}
  {{ $scratch.Set "svgOutput" ($scratch.Get "svgOutput" | replaceRE `<svg ` (print "<svg class='" $class "'")) }}
{{ end }}

{{ $scratch.Get "svgOutput" | safeHTML }}