Fix typo in comment

Author: robsdedude

tests/unit/common/time/_patch.py

@@ -20,7 +20,7 @@
 
 
 # The existence of this class will make the driver's custom date time
-# implementation use it instead of a real clock since its precision it higher
+# implementation use it instead of a real clock since its precision is higher
 # than all the other clocks (only up to nanoseconds).
 class FixedClock(_Clock):
     @classmethod