public async Task<IHttpActionResult> PutDepartment(int id, Department department)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            if (id != department.Id)
            {
                return BadRequest();
            }

            db.Entry(department).State = EntityState.Modified;

            try
            {
                await db.SaveChangesAsync();
            }
            catch (DbUpdateConcurrencyException)
            {
                if (!DepartmentExists(id))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }

            return StatusCode(HttpStatusCode.NoContent);
        }
        // POST: odata/Departments
        public async Task<IHttpActionResult> Post(Department department)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            db.Departments.Add(department);
            await db.SaveChangesAsync();

            return Created(department);
        }
        public async Task<IHttpActionResult> PostDepartment(Department department)
        {
            if (!ModelState.IsValid)
            {
                return BadRequest(ModelState);
            }

            db.Departments.Add(department);
            await db.SaveChangesAsync();

            return CreatedAtRoute("DefaultApi", new { id = department.Id }, department);
        }