Solution: add pre-instance caching to get_property

src/pyEQL/solution.py

@@ -8,6 +8,7 @@
 
 # import libraries for scientific functions
 import math
+from functools import lru_cache
 from typing import Dict, List, Literal, Optional, Union
 
 from iapws import IAPWS95
@@ -92,6 +93,9 @@ def __init__(
         # create a logger attached to this class
         # self.logger = logging.getLogger(type(self).__name__)
 
+        # per-instance cache of get_property calls
+        self.get_property = lru_cache(maxsize=None)(self._get_property)
+
         # initialize the volume with a flag to distinguish user-specified volume
         if volume is not None:
             volume_set = True
@@ -1768,7 +1772,7 @@ def get_mobility(self, solute):
 
         return mobility.to("m**2/V/s")
 
-    def get_property(self, solute, name):
+    def _get_property(self, solute, name):
         """Retrieve a thermodynamic property (such as diffusion coefficient)
         for solute, and adjust it from the reference conditions to the conditions
         of the solution