hadley/ggplot2 — comment on commit a958384341f7bffdb1e2817f9ea6f4b9f3057e88
File:  line 0
By kohske:

This test for zero_range sometimes induces a problem.
For example, the mean of data is very large while the range is narrow.

e.g.)

```R
qplot(1:10, 1e8+runif(10))
qplot(ISOdate(2001, 1, 1, tz = "") + round(runif(100, max = 10)), 1:100)
```

When do we need to test this?