code: public List<String> getProperties(TableRef tableRef) {
          List<String> result = new ArrayList<String>();
          TableMapping tableMapping = mappedClasses.get(tableRef);
          if (tableMapping == null) return result;
          for (ColumnMetaData columnMetaData : tableMapping.getMappedColumns()) {
              ColumnMapping cm = tableMapping.getColumnMapping(columnMetaData);
              result.add(cm.getPropertyName());
          }
          return result;
      }
docs: Returns the property names of the POJO Class to which the specified table is mapped
  <p/>
  <p>If the specified table is not mapped by this instance, it returns an empty <code>List</code>.</p>
  
  @param tableRef the <code>TableRef</code> for the table
  @return list of properties of the class that corresponds with the table identified by the arguments
  @throws IllegalStateException if the map() method has not been invoked first.