template1(test1,test2) {
  variable_1 : input;
  index_1(" 1.0, 2.0");
  index_2(" 1.0, 2.0");
}
templat2(test1,!test2) {
  variable_1 : output;
  index_1(" 1.0, 2.0");
  
}
template3(!test1,test2) {
  variable_1 : time;
  index_2(" 1.0, 2.0");
}
template4(!test1,!test2) {
  variable_1 : time;
  index_1(" 1.0, 2.0");
}

##</code><code>##

 
command line    template selection        reason
test1             template2               test1 ,no test2 
                                          not specified
test2             template3               test2 specified  
                                          test1 not specfied
test1,test2       template1               both are specified

nothing in
command line      template4              both are not 
                                         specified