def deleteFeatures(self,
                       objectIds="",
                       where="",
                       geometryFilter=None,
                       gdbVersion=None,
                       rollbackOnFailure=True
                       ):
        """ removes 1:n features based on a sql statement
            Input:
              objectIds - The object IDs of this layer/table to be deleted
              where - A where clause for the query filter. Any legal SQL
                      where clause operating on the fields in the layer is
                      allowed. Features conforming to the specified where
                      clause will be deleted.
              geometryFilter - a filters.GeometryFilter object to limit
                               deletion by a geometry.
              gdbVersion - Geodatabase version to apply the edits. This
                           parameter applies only if the isDataVersioned
                           property of the layer is true
              rollbackOnFailure - parameter to specify if the edits should
                                  be applied only if all submitted edits
                                  succeed. If false, the server will apply
                                  the edits that succeed even if some of
                                  the submitted edits fail. If true, the
                                  server will apply the edits only if all
                                  edits succeed. The default value is true.
            Output:
               JSON response as dictionary
        """
        dURL = self._url + "/deleteFeatures"
        params = {
            "f": "json",
            'rollbackOnFailure' : rollbackOnFailure
        }
        if gdbVersion is not None:
            params['gdbVersion'] = gdbVersion
        if geometryFilter is not None and \
           isinstance(geometryFilter, filters.GeometryFilter):
            gfilter = geometryFilter.filter
            params['geometry'] = gfilter['geometry']
            params['geometryType'] = gfilter['geometryType']
            params['inSR'] = gfilter['inSR']
            params['spatialRel'] = gfilter['spatialRel']
        if where is not None and \
           where != "":
            params['where'] = where
        if objectIds is not None and \
           objectIds != "":
            params['objectIds'] = objectIds
        result = self._post(url=dURL, param_dict=params,
                               securityHandler=self._securityHandler,
                               proxy_port=self._proxy_port,
                               proxy_url=self._proxy_url)
        self.__init()
        return result