@Override
  public Long decr(final byte[] key) {
    checkIsInMultiOrPipeline();
    client.decr(key);
    return client.getIntegerReply();
  }
@ Override public Long decr ( final byte [ ] key ) { checkIsInMultiOrPipeline ( ) ; client . decr ( key ) ; return client . getIntegerReply ( ) ; }
Decrement the number stored at key by one. If the key does not exist or contains a value of a
wrong type, set the key to the value of "0" before to perform the decrement operation.
<p>
INCR commands are limited to 64 bit signed integers.
<p>
Note: this is actually a string operation, that is, in Redis there are not "integer" types.
Simply the string stored at the key is parsed as a base 10 64 bit signed integer, incremented,
and then converted back as a string.
<p>
Time complexity: O(1)
@see #incr(byte[])
@see #incrBy(byte[], long)
@see #decrBy(byte[], long)
@param key
@return Integer reply, this commands will reply with the new value of key after the increment.