===== decr =====
Decrement a numerical key’s value by the given number if the key/value pair exists.

**syntax:** 
<code>
decr <key> <value> [noreply]
</code>

**parameters:**
  * **key** - The name of the unique key by which data is accessed.
  * **value** - The data that needs to be stored.
  * **noreply** - This **optional** parameter tells the server not to send any reply.

**example:**
<code>
decr mykey 3

2
</code>

**output notes:**
  * **3** → Subtract 3 from the value of "mykey"
  * In this example, if "mykey" had a value of "5", after running **decr**, its value would be "2".

**possible errors:**
  * **NOT_FOUND** - Indicates that the provided key does not exist in the LSMCD server.
  * **CLIENT_ERROR** - Indicates that the value associated with the provided key is not numerical. 
  * **ERROR** - Indicates any other error such as a syntax error.