Implementing the removeMediaCollection method

This is the final method for our service. Its code shouldn't require any more explanations:

removeMediaCollection(identifier: string): Promise<void> { 
    return new Promise<void>((resolve, reject) => { 
        if (!identifier || '' === identifier.trim()) { 
            reject(new Error("The identifier must be provided!")); 
        } 
        console.log(`Removing media collection with the following 
        identifier ${identifier}`); 
 
        this._store.removeItem(identifier) 
            .then(() => { 
                console.log(`Removed the ${identifier} collection 
                successfully!`); 
                resolve(); 
            }) 
            .catch(err => { 
                console.error(`Failed to removed the ${identifier} 
                collection`); 
                reject(err); 
            }); 
    }); 
} 

Great! Our service is now fully implemented. We'll see how it is used later.