code: public static MaskFormat maskFormat(final String mask)
      {
          MaskFormat maskFmt = context.get().getMaskFormat();
          maskFmt.setMask(mask);
          return maskFmt;
      }
docs: <p>
  Returns a {@link MaskFormat} instance for the current thread.
  </p>
  
  @param mask
  The pattern mask
  @return a {@link MaskFormat} instance