cleanup

yt/visualization/plot_container.py

@@ -705,20 +705,6 @@ def _get_axes_unit_labels(self, unit_x, unit_y):
         comoving = False
         hinv = False
         for i, un in enumerate((unit_x, unit_y)):
-            unn = None
-            if hasattr(self.data_source, "axis"):
-                # TODO(4179): remove this (only used for spectral cube)
-                if hasattr(self.ds.coordinates, "default_unit_label"):
-                    axax = getattr(self.ds.coordinates, f"{'xy'[i]}_axis")[
-                        self.data_source.axis
-                    ]
-                    unn = self.ds.coordinates.default_unit_label.get(axax, None)
-            if unn in (1, "1", "dimensionless"):
-                axes_unit_labels[i] = ""
-                continue
-            if unn is not None:
-                axes_unit_labels[i] = _get_units_label(unn).strip("$")
-                continue
             # Use sympy to factor h out of the unit.  In this context 'un'
             # is a string, so we call the Unit constructor.
             expr = Unit(un, registry=self.ds.unit_registry).expr