public String decompress(String compressorName, String compressedString) throws IOException {
    Checks.notNull(compressedString, "compressedString cannot be null");
    Compressor compressor = getCompressor(compressorName);
    return new String(compressor.decompress(base64Decode(compressedString)), DEFAULT_ENCODING);
  }
@Test
  public void testDecompress() throws IOException {
    assertEquals("aaaaaaa", stringCodec.decompress("gzip", "H4sIAAAAAAAAAEtMBAMAdCCLWwcAAAA="));
  }