sub get {
   my ( $self, $arg_ref ) = @_;
   # ...

   ### get needed parameters:
   my @values      = @{ $arg_ref->{'values'} };     # ARRAY: value1, value2,...
   my $table       = $arg_ref->{'table'};      # string
   my $where       = $arg_ref->{'where'};      # sql-string, opt
   my $sort        = $arg_ref->{'sort'};       # sql-string, opt
   ###

   # ...