code: public void setNumShards(final int numShards)
  	{
  		Preconditions.checkArgument(numShards > 0, "A Counter must have at least 1 CounterShard!");
  
  		this.numShards = numShards;
  		this.setUpdatedDateTime(new DateTime(DateTimeZone.UTC));
  	}
docs: Setter for {@code numShards}.
  
  @param numShards
  @throws IllegalArgumentException if {@code numShards} is less-than or equals to zero.