in content/references/java-chassis/1.x/gitbook/gitbook-plugin-fontsettings/fontsettings.js [134:141]
function getThemeId(configName) {
// Search for plugin configured theme
var configTheme = $.grep(THEMES, function(theme) {
return theme.config == configName;
})[0];
// Fallback to default theme
return (!!configTheme)? configTheme.id : 0;
}