Move AxisArray monkey patch to util module so downstream can use it…

… without importing pylsl.

src/ezmsg/lsl/units.py

@@ -5,22 +5,9 @@
 
 import numpy as np
 import pylsl
-
 import ezmsg.core as ez
-from ezmsg.util.messages.axisarray import AxisArray
-
-
-@dataclass
-class CustomAxis(AxisArray.Axis):
-    labels: typing.List[str] = field(default_factory=lambda: [])
-
-    @classmethod
-    def SpaceAxis(cls, labels: typing.List[str]):  # , locs: typing.Optional[npt.NDArray] = None):
-        return cls(unit="mm", labels=labels)
-
 
-# Monkey-patch AxisArray with our customized Axis
-AxisArray.Axis = CustomAxis
+from .util import AxisArray
 
 
 # Reproduce pylsl.string2fmt but add float64 for more familiar numpy usage

src/ezmsg/lsl/util.py

@@ -0,0 +1,17 @@
+from dataclasses import dataclass, field
+import typing
+
+from ezmsg.util.messages.axisarray import AxisArray
+
+
+@dataclass
+class CustomAxis(AxisArray.Axis):
+    labels: typing.List[str] = field(default_factory=lambda: [])
+
+    @classmethod
+    def SpaceAxis(cls, labels: typing.List[str]):  # , locs: typing.Optional[npt.NDArray] = None):
+        return cls(unit="mm", labels=labels)
+
+
+# Monkey-patch AxisArray with our customized Axis
+AxisArray.Axis = CustomAxis