code: public AsciiString toLowerCase() {
          boolean lowercased = true;
          int i, j;
          final int len = length() + arrayOffset();
          for (i = arrayOffset(); i < len; ++i) {
              byte b = value[i];
              if (b >= 'A' && b <= 'Z') {
                  lowercased = false;
                  break;
              }
          }
  
          // Check if this string does not contain any uppercase characters.
          if (lowercased) {
              return this;
          }
  
          final byte[] newValue = PlatformDependent.allocateUninitializedArray(length());
          for (i = 0, j = arrayOffset(); i < newValue.length; ++i, ++j) {
              newValue[i] = toLowerCase(value[j]);
          }
  
          return new AsciiString(newValue, false);
      }
docs: Converts the characters in this string to lowercase, using the default Locale.
  
  @return a new string containing the lowercase characters equivalent to the characters in this string.