old_contents: from regression import *
  
  __doc__ = """
  >>> t = Table(bill)
  >>> print pretty_html(t.render())
  <tbody>
   <tr>
    <td class="table_label">
     Email:
    </td>
    <td class="table_field">
     bill@example.com
    </td>
   </tr>
   <tr>
    <td class="table_label">
     Password:
    </td>
    <td class="table_field">
     1234
    </td>
   </tr>
   <tr>
    <td class="table_label">
     Name:
    </td>
    <td class="table_field">
     Bill
    </td>
   </tr>
   <tr>
    <td class="table_label">
     Orders:
    </td>
    <td class="table_field">
     Quantity: 10
    </td>
   </tr>
  </tbody>
  
  >>> t = TableCollection(User, [bill])
  >>> print pretty_html(t.render().strip())
  <thead>
   <tr>
    <th>
     Email:
    </th>
    <th>
     Password:
    </th>
    <th>
     Name:
    </th>
    <th>
     Orders:
    </th>
   </tr>
  </thead>
  <tbody>
   <tr>
    <td>
     bill@example.com
    </td>
    <td>
     1234
    </td>
    <td>
     Bill
    </td>
    <td>
     Quantity: 10
    </td>
   </tr>
  </tbody>
  """
  
  if __name__ == '__main__':
      import doctest
      doctest.testmod()
  
new_contents: from regression import *
  
  __doc__ = """
  >>> t = Table(bill)
  >>> print pretty_html(t.render())
  <tbody>
   <tr>
    <td class="table_label">
     Email:
    </td>
    <td class="table_field">
     bill@example.com
    </td>
   </tr>
   <tr>
    <td class="table_label">
     Password:
    </td>
    <td class="table_field">
     1234
    </td>
   </tr>
   <tr>
    <td class="table_label">
     Name:
    </td>
    <td class="table_field">
     Bill
    </td>
   </tr>
   <tr>
    <td class="table_label">
     Orders:
    </td>
    <td class="table_field">
     Quantity: 10
    </td>
   </tr>
  </tbody>
  
  >>> t = TableCollection(User, [bill])
  >>> print pretty_html(t.render().strip())
  <thead>
   <tr>
    <th>
     Email:
    </th>
    <th>
     Password:
    </th>
    <th>
     Name:
    </th>
    <th>
     Orders:
    </th>
   </tr>
  </thead>
  <tbody>
   <tr>
    <td>
     bill@example.com
    </td>
    <td>
     1234
    </td>
    <td>
     Bill
    </td>
    <td>
     Quantity: 10
    </td>
   </tr>
  </tbody>
  
  >>> t = TableCollection(User, [bill, john])
  >>> t.add(Field('link', type=types.String, value=lambda item: '<a href=%d>link</a>' % item.id))
  >>> print pretty_html(t.render().strip())
  <thead>
   <tr>
    <th>
     Email:
    </th>
    <th>
     Password:
    </th>
    <th>
     Name:
    </th>
    <th>
     Orders:
    </th>
    <th>
     Link:
    </th>
   </tr>
  </thead>
  <tbody>
   <tr>
    <td>
     bill@example.com
    </td>
    <td>
     1234
    </td>
    <td>
     Bill
    </td>
    <td>
     Quantity: 10
    </td>
    <td>
     <a href="1">
      link
     </a>
    </td>
   </tr>
   <tr>
    <td>
     john@example.com
    </td>
    <td>
     5678
    </td>
    <td>
     John
    </td>
    <td>
     Quantity: 5
    </td>
    <td>
     <a href="2">
      link
     </a>
    </td>
   </tr>
  </tbody>
  """
  
  if __name__ == '__main__':
      import doctest
      doctest.testmod()
  
subject: add test for value=callable feature