has 'handler' => ( isa => 'FileHandle', is => 'rw' );

sub openHandler {
    my $self = shift;
    open( $self->handler, '<', $self->file ) or croak "Can't open file";
}

sub closeHandler {
    my $self = shift;
    close $self->handler;
}

sub readLine {
    my $self = shift;
    return <$self->handler>;
}