Add missing import.

Author: lohedges

src/BioSimSpace/FreeEnergy/_relative.py

@@ -1720,6 +1720,7 @@ def _analyse_somd(work_dir=None, estimator="MBAR", method="alchemlyb", **kwargs)
 
         import numpy as _np
 
+        from .. import _Utils
         from .. import Units as _Units
         from .._Exceptions import AnalysisError as _AnalysisError