#-- the "-varbindlist' array ref is assigned to $trios
   my $pairs = [];
   for (my $i = 0; $i < $#{$trios}; $i += 3) {
      if ($trios->[$i] !~ /^\.?\d+\.\d+(?:\.\d+)*/) {
         return $this->_error('Expected OBJECT IDENTIFIER in dotted notation');
      }
      push(@{$pairs},
         OBJECT_IDENTIFIER, $trios->[$i], $trios->[$i+1], $trios->[$i+2]
      );
   }