use strict; use warnings;
use YAML qw( LoadFile Dump Load );
use Data::Dump qw( dump );

my $in = "  FOO\nBAR  BAZ\n";
my $out = Load( Dump( $in ) );
print dump( $in, $out );

------ output -----
(
    "  FOO\nBAR  BAZ\n",
    " FOO\nBAR BAZ\n",
)