public boolean getColUpdated(int idx) {
        return colsChanged.get(idx);
    }
Indicates whether the designated column of this <code>Row</code> object
has been changed.
@param idx the index into the <code>BitSet</code> object maintained by
           this <code>Row</code> object to keep track of which column
           values have been modified; the index of the first bit is
           <code>0</code>
@return <code>true</code> if the designated column value has been changed;
        <code>false</code> otherwise
src/main/java/org/replicadb/rowset/sun/rowset/internal/Row.java