I saw that in most samples SqlCommand was used like this

using (SqlConnection con = new SqlConnection(CNN_STRING))
{
    using (SqlCommand cmd = new SqlCommand("Select ID,Name From Person", con))
    {
        SqlDataAdapter da = new SqlDataAdapter(cmd);
        DataSet ds =new DataSet();
       
da.Fill(ds);           
        return ds;
    }
}

I know why we are using "using" statement. But SqlCommand doesn't inlcude Close() method, so should we really use it within using statement