formatBoolean

def formatBoolean = { attrs ->
         if (!attrs.containsKey("boolean"))
             throwTagError("Tag [formatBoolean] is missing required attribute [boolean]")
         def b = attrs.get("boolean")
         if (b == null) {
             return
         }
         else if (!(b instanceof Boolean)) {
             b = Boolean.valueOf(b)
         }
         if (b) {
             out << (attrs["true"] ?: message(code:"boolean.true", default: message(code:"default.boolean.true", default:"True")))
         }
         else {
             out << (attrs["false"] ?: message(code:"boolean.false", default: message(code:"default.boolean.false", default:"False")))
         }
     }