code: public static String getMIMEType(final String pFileExt) {
          List<String> types = sExtToMIME.get(StringUtil.toLowerCase(pFileExt));
          return (types == null || types.isEmpty()) ? null : types.get(0);
      }
docs: Returns the default MIME type for the given file extension.
  
  @param pFileExt the file extension
  
  @return a {@code String} containing the MIME type, or {@code null} if
  there are no known MIME types for the given file extension.