function filter(mMap) {
			if (!sGroupId) {
				return Object.keys(mMap);
			}

			return sGroupId in mMap ? [sGroupId] : [];
		}
Returns <code>true</code> if there are pending changes for the given group ID.

@param {string} [sGroupId]
  The ID of the group to be checked; if not supplied all groups are checked for pending
  changes (since 1.70.0)
@returns {boolean} <code>true</code> if there are pending changes

@public