code: public static String sha1hmac(String key, String plaintext, int encoding)
  	{
  		byte[] signature = sha1hmac(key.getBytes(), plaintext.getBytes());
  
  		return encode(signature, encoding);
  	}
docs: Performs HMAC-SHA1 on the UTF-8 byte representation of strings, returning the hexidecimal hash as a result
  
  @param key
  @param plaintext
  
  @return