Odd number of elements in hash assignment at test.pl line 15.
map ver
$VAR1 = {
          '' => undef,   <====THIS ONE
          'a2' => 'vala2',
          'a1' => 'vala1',
          'a3' => 'vala3'
        };
grep,map ver
$VAR1 = {
          'a2' => 'vala2',
          'a1' => 'vala1',
          'a3' => 'vala3'
        };
foreach ver
$VAR1 = {
          'a2' => 'vala2',
          'a1' => 'vala1',
          'a3' => 'vala3'
        };