code: @NotNull
      public static String unescapeChar(@NotNull final String string, final char toUnescape) {
          final String toUnescapeStr = String.valueOf(toUnescape);
          return string.replaceAll("\\\\" + toUnescapeStr, toUnescapeStr);
      }
docs: Unescape all the occurrences of the <toUnescape> character from the <string>
  
  @param string     the string from which to unescape the character
  @param toUnescape the character to unescape
  @return a new string with the unescaped <toUnescape> character