<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def __parseColumns(self):
 """Returns the list of columns related to the dataset."""

        columns = []
        if self.__dataItem.has_key('columnModel'):
            for column in self.__dataItem['columnModel']:
                columns.append(Column(column))
        return columns