code: public String getUnitDisplayName(MeasureUnit unit) {
          FormatWidth width = getRegularWidth(formatWidth);
          Map<FormatWidth, String> styleToDnam = cache.unitToStyleToDnam.get(unit);
          if (styleToDnam == null) {
              return null;
          }
  
          String dnam = styleToDnam.get(width);
          if (dnam != null) {
              return dnam;
          }
          FormatWidth fallbackWidth = cache.widthFallback[width.ordinal()];
          if (fallbackWidth != null) {
              dnam = styleToDnam.get(fallbackWidth);
          }
          return dnam;
      }
docs: Gets the display name of the specified {@link MeasureUnit} corresponding to the current
  locale and format width.
  @param unit  The unit for which to get a display name.
  @return  The display name in the locale and width specified in
  {@link MeasureFormat#getInstance}, or null if there is no display name available
  for the specified unit.
  
  @hide draft / provisional / internal are hidden on Android