add solver_base

Author: k-yoshimi

src/hwave/solver/uhfr.py

@@ -1075,6 +1075,8 @@ def _check_range(self):
             logger.error(f"Exchange validation failed: {e}")
             raise
 
+from .base import solver_base
+
 class UHFr(solver_base):
     """Main unrestricted Hartree-Fock solver class.