'show( self, trans, id, history_id, **kwd )
* GET /api/histories/{history_id}/contents/{id}
return detailed information about an HDA within a history
.. note:: Anonymous users are allowed to get their current history contents
:type   id:         str
:param  id:        the encoded id of the HDA to return
:type   history_id: str
:param  history_id: encoded id string of the HDA\'s History
:rtype:     dict
:returns:   dictionary containing detailed HDA information'

@expose_api_anonymous
def show(self, trans, id, history_id, **kwd):

    contents_type = kwd.get('type', 'dataset')
    if (contents_type == 'dataset'):
        return self.__show_dataset(trans, id, **kwd)
    elif (contents_type == 'dataset_collection'):
        return self.__show_dataset_collection(trans, id, history_id, **kwd)
    else:
        return self.__handle_unknown_contents_type(trans, contents_type)
