Update() public method

Update existing project.
public Update ( string projectId, string name = null, string description = null ) : Task
projectId string Existing project's id.
name string New name of specified project.
description string New description of specified project.
return Task
 public async Task Update_WithNoProjectId_ThrowsException(ProjectSyncanoClient client)
 {
     try
     {
         //when
         await client.Update(null);
         throw new Exception("Update should throw an exception");
     }
     catch (Exception e)
     {
         //then
         e.ShouldBeType<ArgumentNullException>();
     }
 }
        public async Task Update_WithNoNewValues(ProjectSyncanoClient client)
        {
            //given
            string projectName = "UpdateProject test " + DateTime.Now.ToLongTimeString() + " " +
                                 DateTime.Now.ToShortDateString();

            var project = await client.New(projectName);

            //when
            project = await client.Update(project.Id);

            //then
            project.ShouldNotBeNull();
            project.Name.ShouldEqual(projectName);
            project.Description.ShouldBeNull();

            //cleanup
            await client.Delete(project.Id);
        }
 public async Task Update_WithInvalidProjectId_ThrowsException(ProjectSyncanoClient client)
 {
     try
     {
         //when
         await client.Update("abc");
         throw new Exception("Update should throw an exception");
     }
     catch (Exception e)
     {
         //then
         e.ShouldBeType<SyncanoException>();
     }
 }
        public async Task Update_CreatesProjectObjectWithNewValues(ProjectSyncanoClient client)
        {
            //given
            var projectName = "UpdateProject test " + DateTime.Now.ToLongTimeString() + " " +
                                 DateTime.Now.ToShortDateString();
            var projectNewName = "UpdateProject test new name" + DateTime.Now.ToLongTimeString() + " " +
                                 DateTime.Now.ToShortDateString();
            const string projectOldDescription = "qwerty";
            const string projectNewDescription = "abc";
            var project = await client.New(projectName, projectOldDescription);

            //when
            project = await client.Update(project.Id, projectNewName, projectNewDescription);
            
            //then
            project.ShouldNotBeNull();
            project.Name.ShouldEqual(projectNewName);
            project.Description.ShouldEqual(projectNewDescription);

            //cleanup
            await client.Delete(project.Id);
        }