为新类定义S3"Math"组泛型时出现意外的log2错误

我正在尝试将S3"Math"组泛型用于自定义类.但是我得到了一个奇怪的结果:log()同时工作log2并log10产生错误.以下是一个最小的例子:

# simple class with just the new name
lameclass <- function(x) {
  class(x) <- append(class(x), "lame")
  x
}

# It prints something when Math generics methods are used
Math.lame <- function(x, ...) {
  print("I am lame")
  NextMethod()
}

# an object of the class
lamevector <- lameclass(1:10)

> class(lamevector)
[1] "integer" "lame"

现在试着打电话log:

log(lamevector)
[1] "I am lame"
[1] 0.0000000 0.6931472 1.0986123 1.3862944 1.6094379 1.7917595 1.9459101 2.0794415 2.1972246 2.3025851

基数为2:

log(lamevector, 2)
[1] "I am lame"
[1] 0.000000 1.000000 1.584963 2.000000 2.321928 2.584963 2.807355 3.000000 3.169925 3.321928

以上都是有效的.但现在log2包装:

log2(lamevector)
[1] "I am lame"
[1] "I am lame"
Error in log2.default(1:10, 2) :
  2 arguments passed to 'log2' which requires 1

也许有人可以帮我搞清楚这里发生了什么？log2实际上经历了2次通用数学定义而失败了吗？