  We test whether the population of "extreme" trans-Neptunian objects (eTNOs)
detected in the Y4 Dark Energy Survey (DES) data exhibit azimuthal asymmetries
which might be evidence of gravitational perturbations from an unseen
super-Earth in a distant orbit. By rotating the orbits of the detected eTNOs,
we construct a synthetic population which, when subject to the DES selection
function, reproduces the detected distribution of eTNOs in the orbital elements
$a,e,$ and $i$ as well as absolute magnitude $H$, but has uniform distributions
in mean anomaly $M$, longitude of ascending node $\Omega,$ and argument of
perihelion $\omega.$ We then compare the detected distributions in each of
$\Omega, \omega,$ and $\varpi\equiv\Omega+\omega$ to those expected from the
isotropic population, using Kuiper's variant of the Kolmogorov-Smirnov test.
The three angles are tested for each of 4 definitions of the eTNO population,
choosing among $a>(150,250)$ AU and perihelion $q>(30,37)$ AU. These choices
yield 3--7 eTNOs in the DES Y4 sample. Among the twelve total tests, two have
the likelihood of drawing the observed angles from the isotropic population at
$p<0.05.$ The 3 detections at $a>250, q>37$ AU, and the 4 detections at $a>250,
q>30$ AU, have $\Omega$ distribution with $p=0.03$ of coming from the isotropic
construction, but this is not strong evidence of anisotropy given the 12
different tests. The DES data taken on their own are thus consistent with
azimuthal isotropy and do not require a "Planet 9" hypothesis. The limited sky
coverage and object count mean, however, that the DES data by no means falsify
this hypothesis.
