function _handleSuccess (oData) {
				// Remove request from array
				var idx = this._aPendingSubtreeRequests.indexOf(oRequest);
				this._aPendingSubtreeRequests.splice(idx, 1);

				resolve({
					oData: oData,
					sParent: oRequest.sParent,
					iLevel: oRequest.iLevel
				});
			}
Loads the complete subtree of a given node up to a given level

@param {object} oParentNode The root node of the requested subtree
@param {int} iLevel The maximum expansion level of the subtree
@return {Promise<Object>} Promise that resolves with the response data, parent key and level.
	 				It rejects with the error object which is returned from the server.

@private