@ Override public Observable < Void > addTags ( Metric < ? > metric , Map < String , String > tags ) { try { checkArgument ( tags != null , "Missing tags" ) ; checkArgument ( isValidTagMap ( tags ) , "Invalid tags; tag key is required" ) ; } catch ( Exception e ) { return Observable . error ( e ) ; } return dataAccess . insertIntoMetricsTagsIndex ( metric , tags ) . concatWith ( dataAccess . addTags ( metric , tags ) ) . toList ( ) . map ( l -> null ) ; }
functionality into a separate class .