se adiciona archivo faltante

FossilOrigin-Name: 9b0c4d69d898ddbcd9279b3055e72df525feaefb0d46700dc6c019acdba01e80

facho/model/fields/function.py

@@ -0,0 +1,24 @@
+from .field import Field
+from .model import Model
+
+class Function(Field):
+    def __init__(self, getter, setter=None, field=None):
+        self.field = field
+        self.getter = getter
+        self.setter = setter
+
+    def __get__(self, inst, cls):
+        if inst is None:
+            return self
+        assert self.name is not None
+
+        if self.field is None:
+            return self._call(inst, self.getter, self.name)
+        else:
+            obj = Model(self.field)
+            return self._call(inst, self.getter, self.name, obj)
+
+    def __set__(self, inst, value):
+        if self.setter is None:
+            return super().__set__(self.name, value)
+        self._call(inst, self.setter, self.name, value)