question: @ Override public boolean is_tail ( ) { Collection < BrdItem > contact_list = get_normal_contacts ( ) ; if ( contact_list . size ( ) <= 1 ) { return true ; } Iterator < BrdItem > iter = contact_list . iterator ( ) ; BrdItem curr_contact_item = iter . next ( ) ; int first_contact_first_layer = curr_contact_item . first_layer ( ) ; int first_contact_last_layer = curr_contact_item . last_layer ( ) ; while ( iter . hasNext ( ) ) { curr_contact_item = iter . next ( ) ; if ( curr_contact_item . first_layer ( ) != first_contact_first_layer || curr_contact_item . last_layer ( ) != first_contact_last_layer ) { return false ; } } return true ; }
target:  Checks, if the Via has contacts on at most 1 layer.