software/erp5/test: make utility methods classmethod

so that we can use them in setUpClass

software/erp5/test/test/__init__.py

@@ -49,17 +49,20 @@ def setUpModule():
 class ERP5InstanceTestCase(SlapOSInstanceTestCase):
   """ERP5 base test case
   """
-  def getRootPartitionConnectionParameterDict(self):
+  @classmethod
+  def getRootPartitionConnectionParameterDict(cls):
     """Return the output paramters from the root partition"""
     return json.loads(
-        self.computer_partition.getConnectionParameterDict()['_'])
+        cls.computer_partition.getConnectionParameterDict()['_'])
 
-  def getComputerPartition(self, partition_reference):
-    for computer_partition in self.slap.computer.getComputerPartitionList():
+  @classmethod
+  def getComputerPartition(cls, partition_reference):
+    for computer_partition in cls.slap.computer.getComputerPartitionList():
       if partition_reference == computer_partition.getInstanceParameter(
           'instance_title'):
         return computer_partition
 
-  def getComputerPartitionPath(self, partition_reference):
-    partition_id = self.getComputerPartition(partition_reference).getId()
-    return os.path.join(self.slap._instance_root, partition_id)
+  @classmethod
+  def getComputerPartitionPath(cls, partition_reference):
+    partition_id = cls.getComputerPartition(partition_reference).getId()
+    return os.path.join(cls.slap._instance_root, partition_id)