Make node arg options and default required to True for GlobalID.

Author: markus

graphene/relay/node.py

@@ -35,9 +35,9 @@ class Meta:
 
 class GlobalID(Field):
 
-    def __init__(self, node, *args, **kwargs):
-        super(GlobalID, self).__init__(ID, *args, **kwargs)
-        self.node = node
+    def __init__(self, node=None, required=True, *args, **kwargs):
+        super(GlobalID, self).__init__(ID, required=required, *args, **kwargs)
+        self.node = node or Node
 
     @staticmethod
     def id_resolver(parent_resolver, node, root, args, context, info):
@@ -52,7 +52,7 @@ class NodeMeta(InterfaceMeta):
 
     def __new__(cls, name, bases, attrs):
         cls = InterfaceMeta.__new__(cls, name, bases, attrs)
-        cls._meta.fields['id'] = GlobalID(cls, required=True, description='The ID of the object.')
+        cls._meta.fields['id'] = GlobalID(cls, description='The ID of the object.')
         return cls