# Functions
CreateMongoDBClient will create a new mongo db client instance.
NewClient will create a new mongodb client instance.
# Constants
UsersCollectionID specifies mongodb collection for users.
# Variables
ErrCollectionNotFound signals that provided mongodb collection is not available.
ErrEmptyMongoDBName signals that an empty db name has been provided.
ErrNilMongoDBClient signals that a nil mongodb client has been provided.
# Interfaces
MongoDBClient defines what a mongodb client should do.
# Type aliases
CollectionID defines mongodb collection type.