javax.swing.DefaultRowSorter spec contains a few vaguenesses

1) Method setRowFilter is described by the following way:

"public void setRowFilter(RowFilter filter)

    Sets the filter that determines which rows, if any, should be hidden from the view. The filter is applied before sorting. A value of null indicates all values from the model should be included."

- But there is not noted, that this method triggers a sort.
- "The filter is applied before sorting." - what does it mean? Is the order important?

2) Methods rowsDeleted, rowsUpdated, rowsInserted throw IllegalArgumentException.
But spec contains only:
Throws:
    java.lang.IllegalArgumentException
without any description of cases this exception is thrown.

3) It would be nice to note that method getComparator() must not return null.