public Reader getCharacterStream(int columnIndex) throws SQLException {
        checkState();

        return rs.getCharacterStream(columnIndex);
    }
Gets the value of the designated column in the current row
of this rowset's <code>ResultSet</code> object as a
<code>java.io.Reader</code> object.
@return a <code>java.io.Reader</code> object that contains the column
value; if the value is SQL <code>NULL</code>, the value returned is
<code>null</code>.
@param columnIndex the first column is 1, the second is 2, and so on
src/main/java/org/replicadb/rowset/sun/rowset/JdbcRowSetImpl.java