docs: protected static MethodHandle addTransformer(MethodHandle handle, int pos, Object arg, Class parameter) {
          MethodHandle transformer=null;
          if (arg instanceof GString) {
              transformer = TO_STRING;
          } else if (arg instanceof Closure) {
              transformer = createSAMTransform(arg, parameter);
          } else if (Number.class.isAssignableFrom(parameter)) {
              transformer = selectNumberTransformer(parameter, arg);
          } else if (parameter.isArray()) {
              transformer =  MethodHandles.insertArguments(AS_ARRAY, 1, parameter);
          }
          if (transformer==null) throw new GroovyBugError("Unknown transformation for argument "+arg+" at position "+pos+" with "+arg.getClass()+" for parameter of type "+parameter);
          return applyUnsharpFilter(handle, pos, transformer);
      }