Add missing FunctionGraph unit tests

tests/gof/utils.py

+import numpy as np
+
 from theano.gof.graph import Apply, Variable
 from theano.gof.op import Op
 from theano.gof.type import Type
@@ -20,10 +22,25 @@ class MyType(Type):
         return hash(MyType)
 
 
+class MyType2(Type):
+    def filter(self, data):
+        return data
+
+    def __eq__(self, other):
+        return isinstance(other, MyType)
+
+    def __hash__(self):
+        return hash(MyType)
+
+
 def MyVariable(name):
     return Variable(MyType(), None, None, name=name)
 
 
+def MyVariable2(name):
+    return Variable(MyType2(), None, None, name=name)
+
+
 class MyOp(Op):
     def __init__(self, name, dmap=None, x=None):
         self.name = name
@@ -40,6 +57,9 @@ class MyOp(Op):
         outputs = [MyType()()]
         return Apply(self, inputs, outputs)
 
+    def perform(self, node, inputs, outputs):
+        outputs[0] = np.array(inputs)
+
     def __str__(self):
         return self.name