void addArg(@NonNull String format,@Nullable Object arg,boolean addSeparatorBefore){
  if (addSeparatorBefore) {
    builder.append(", ");
  }
  builder.append(format);
  if (arg != null) {
    args.add(arg);
  }
}

void addArg ( @ NonNull String format , @ Nullable Object arg , boolean addSeparatorBefore ) { if ( addSeparatorBefore ) { builder . append ( ", " ) ; } builder . append ( format ) ; if ( arg != null ) { args . add ( arg ) ; } }
add a string format and the corresponding object .
