/// <summary>
        /// The Delete.
        /// </summary>
        /// <param name="paperHashes">The paperHashes<see cref="Models.PaperHashes"/>.</param>
        /// <returns>The <see cref="Task"/>.</returns>
        public async Task Delete(Models.PaperHashes paperHashes)
        {
            var check = await Read(paperHashes);

            if (check != null)
            {
                _db.PaperHashes.Remove(check);
                await _db.SaveChangesAsync();
            }
        }
        /// <summary>
        /// The Update.
        /// </summary>
        /// <param name="paperHashes">The paperHashes<see cref="Models.PaperHashes"/>.</param>
        /// <returns>The <see cref="Task{Models.PaperHashes}"/>.</returns>
        public async Task <Models.PaperHashes> Update(Models.PaperHashes paperHashes)
        {
            var check = await Read(paperHashes);

            if (check != null)
            {
                _db.PaperHashes.Update(paperHashes);
                await _db.SaveChangesAsync();

                return(paperHashes);
            }
            return(paperHashes);
        }
        /// <summary>
        /// The Create.
        /// </summary>
        /// <param name="paperHashes">The paperHashes<see cref="Models.PaperHashes"/>.</param>
        /// <returns>The <see cref="Task{Models.PaperHashes}"/>.</returns>
        public async Task <Models.PaperHashes> Create(Models.PaperHashes paperHashes)
        {
            var check = await Read(paperHashes);

            if (check == null)
            {
                await _db.PaperHashes.AddAsync(paperHashes);

                await _db.SaveChangesAsync();

                return(paperHashes);
            }
            return(paperHashes);
        }
 /// <summary>
 /// The Read.
 /// </summary>
 /// <param name="paperHashes">The paperHashes<see cref="Models.PaperHashes"/>.</param>
 /// <returns>The <see cref="Task{Models.PaperHashes}"/>.</returns>
 public async Task <Models.PaperHashes> Read(Models.PaperHashes paperHashes)
 {
     return(await _db.PaperHashes.FirstOrDefaultAsync(x => x.PaperId == paperHashes.PaperId && x.HashTagId == paperHashes.HashTagId));
 }