$self->{'copybooks'} = {
  'cpy00' => Cobol::Copybook->new({filehandle => \*DATA, filter => '00'}),
  'cpy01' => Cobol::Copybook->new({filehandle => \*DATA, filter => '01'}),
  'cpy04' => Cobol::Copybook->new({filehandle => \*DATA, filter => '04'})
};