wandb_sweep_start_agent Subroutine

  subroutine wandb_sweep_start_agent(sweep_id, project, count, entity)
    !! Start a wandb sweep agent in a background Python thread.
    !!
    !! ## Usage pattern
    !!
    !! ```fortran
    !! call wandb_sweep(config=cfg, project="my-proj", sweep_id=sid)
    !! call wandb_sweep_start_agent(sid, "my-proj", count=5)
    !! do i = 1, 5
    !!    call wandb_sweep_next_params(params_json)
    !!    ! parse params_json, train, log ...
    !!    call wandb_sweep_run_done()
    !! end do
    !! call wandb_shutdown()
    !! ```
    character(len=*),           intent(in) :: sweep_id
    character(len=*),           intent(in) :: project
    integer,                    intent(in) :: count
    character(len=*), optional, intent(in) :: entity

    character(len=:), allocatable :: c_entity
    integer(c_int) :: rc

    if(present(entity))then
       c_entity = trim(entity) // c_null_char
    else
       c_entity = c_null_char
    end if

    rc = wandb_sweep_start_agent_c( &
         trim(sweep_id) // c_null_char, &
         trim(project)  // c_null_char, &
         c_entity,                       &
         int(count, c_int)               &
    )

    if(rc /= 0)then
       write(0,*) "[wf] WARNING: wandb_sweep_start_agent failed (rc=", rc, ")"
    end if

  end subroutine wandb_sweep_start_agent