title: Test ResultSet to see if it contains a column label
body: <p>Is it possible to check a ResultSet to see if it contains a column label for the current row. I would assume that it is backed by some kind of Map, so providing an rs.contains("label") method can't be that expensive, but I can't find one in the javadoc.</p>
  
  <p>The current way I'm testing for the presence of a label is:</p>
  
  <pre><code>BigDecimal bid;
      try {
          bid = rs.getBigDecimal("bid");
      }
      catch(final SQLException e) {
          bid = null;
      }
  </code></pre>
  
  <p>But this seems untidy to me, and will be unreadable if you want to test multiple rows in this manner.</p>