def update(bucket)
			@queries['update'].execute(bucket.current, bucket.last_refill, bucket.total_used, bucket.name)
		end
def update(bucket)
			@queries['update'].execute(bucket.current, bucket.last_refill, bucket.total_used, bucket.name)
		end
updates the key fields that need updating into the storage
 this is often cheaper for certain types of storage than using set()
 * *Args*    :
   - +bucket+ -> the Bucket to update.  The <tt>name</tt> field in the Bucket option will be used as a key.
 * *Returns* :
   - an empty result set
 * *Raises* :
   - +Mysql::Error+ -> any issue with the connection to the database or the SQL statements