code: public PropertyColumn addPropertyColumn(String propertyName, Class<?> propertyType)
      {
          String[] headerKeys = getMessageResolver().getMessageKeys(this.id, propertyName, MessageConstants.HEADER);
          Accessor accessor = ClassUtils.getAccessorForProperty(entityClass, propertyName);
          if (propertyType == null)
              propertyType = accessor.getPropertyType();
          PropertyColumn propertyColumn = new PropertyColumn(propertyName, accessor, propertyType);
          if (String.class.isAssignableFrom(propertyColumn.getType()))
              propertyColumn.setFilterColumn(true);
          propertyColumn.setHeaderKeys(headerKeys);
          columns.add(propertyColumn);
          return propertyColumn;
      }
docs: Create and add a column for the given property. Property type is passed or determined (when
  <code>null</code>) by examining the {@link Accessor} and headerKeys are added based upon the id of
  the {@link PropertyColumnTableDescription}, the propertyName and the postfix "HEADER".
  
  @param propertyName
  name of the property.
  @param propertyType
  type of the property. If <code>null</code> a type will be determined by examining the
  accessor method.