code: public final void setProgressFormat(@NonNull final String progressFormat) {
          Condition.INSTANCE.ensureNotNull(progressFormat, "The progress format may not be null");
          Condition.INSTANCE.ensureNotEmpty(progressFormat, "The progress format may not be empty");
          this.progressFormat = progressFormat;
          adaptProgress();
      }
docs: Sets the string, which should be used to format the progress, which is shown, when the
  activity is used as a wizard.
  
  @param progressFormat
  The string, which should be set, as a {@link String}. The string may neither be null,
  nor empty. It must be formatted according to the following syntax: "*%d*%d*%s*"