private static List < String > getVariantKeys ( String variantKeyPrefix , Collection < String > variants ) { List < String > variantKeys = new ArrayList <> ( ) ; for ( String variant : variants ) { if ( variant == null ) { variant = "" ; } if ( variantKeyPrefix == null ) { variantKeys . add ( variant ) ; } else { variantKeys . add ( variantKeyPrefix + variant ) ; } } return variantKeys ; }
Returns the variant keys