docs: function getFontFeatureSettingsPrevTo(decl) {
    var fontFeatureSettings = null;
    decl.parent.walkDecls(function(decl) {
      if (decl.prop === "font-feature-settings") {
        fontFeatureSettings = decl;
      }
    })
  
    if (fontFeatureSettings === null) {
      fontFeatureSettings = decl.clone()
      fontFeatureSettings.prop = "font-feature-settings"
      fontFeatureSettings.value = ""
      decl.parent.insertBefore(decl, fontFeatureSettings)
    }
    return fontFeatureSettings
  }