package FileReader;
use Moose;
use Moose::Util::TypeConstraints;
use IO::File;

subtype 'FileHandleFromStr', as 'FileHandle';

coerce 'FileHandleFromStr', from 'Str', via { IO::File->new("< $_") };

has file => (
    is     => 'ro',
    isa    => 'FileHandleFromStr',
    coerce => 1,
);

sub read_next_line {
    my $self = shift;
    return $self->file->getline;
}

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