Add a shortcut to obtain the instance of a possibly existing cnfvar

This is added in the cnf list query mixin which is where we have
all shortcut, syntactic sugar, and ease of use methods.

diff --git a/src/cnfvar/model.py b/src/cnfvar/model.py
index 827ff99..168f5db 100644 (file)
--- a/src/cnfvar/model.py
+++ b/src/cnfvar/model.py
@@ -929,6 +929,10 @@ class CnfListQueryingMixin(BaseCnfList):
         """Shortcut method for getting the first item with a given instance."""
         return self.with_instance(instance).first(default=default)
 
+    def highest_instance(self):
+        """Shortcut method for getting the next instance in a list of items."""
+        return max([c.instance for c in self]) if len(self) > 0 else -1
+
 
 ###############################################################################
 # PUBLIC CLASSES