# @options has options for ssh itself.
my @cmd = (
           qw(ssh), @options,
           $self->usernode(),
           $self->quote_cmd(@cmd)
          );

# for testing purposes, allow proxying.
if ($ENV{SSH_TEST_PROXY})
{
  @cmd = (
          qw(ssh), @options,
          $ENV{SSH_TEST_PROXY},
          $self->quote_cmd(@cmd)
         );
}