docs: public static void downto(Float self, Number to, @ClosureParams(FirstParam.class) Closure closure) {
          float to1 = to.floatValue();
          if (self >= to1) {
              for (float i = self; i >= to1; i--) {
                  closure.call(i);
              }
          } else
              throw new GroovyRuntimeException("The argument (" + to +
                      ") to downto() cannot be greater than the value (" + self + ") it's called on.");    }