package MyClass;
sub new {
  my $class= shift;
  my %self= @_ ==1 && ref $_[0] eq 'HASH'? %{ $_[0] } : @_;
  bless \%self, $class;
}
sub attribite1 {  # read-only accessor
  $_[0]{attribute1}
}
sub attribute2 {  # read-write accessor
  $_[0]{attribute2}= $_[1] if @_ > 1;
  $_[0]{attribute2}
}