Remove xsi_type from Indentity binding.

Author: emmanvg

stix/bindings/stix_common.py

@@ -606,22 +606,12 @@ def buildChildren(self, child_, node, nodeName_, fromsubclass_=False):
             obj_.build(child_)
             self.set_Description(obj_)
         elif nodeName_ == 'Identity':
-            type_name_ = child_.attrib.get('{http://www.w3.org/2001/XMLSchema-instance}type')
-            if type_name_ is None:
-                type_name_ = child_.attrib.get('type')
-            if type_name_ is not None:
-                type_names_ = type_name_.split(':')
-                if len(type_names_) == 1:
-                    type_name_ = type_names_[0]
-                else:
-                    type_name_ = type_names_[1]
 
-                if type_name_ == "CIQIdentity3.0InstanceType":
-                    import stix.bindings.extensions.identity.ciq_identity_3_0 as ciq_identity_binding
-                    obj_ = ciq_identity_binding.CIQIdentity3_0InstanceType.factory()
-            else:
-                obj_ = IdentityType.factory() # IdentityType is not abstract
+            from stix.bindings.extensions.identity import ciq_identity_3_0
 
+            # Look for xsi:type. If not there, build an instance of
+            # IdentityType
+            obj_ = lookup_extension(child_, IdentityType).factory()
             obj_.build(child_)
             self.set_Identity(obj_)
         elif nodeName_ == 'Role':
@@ -1277,7 +1267,6 @@ def __init__(self, idref=None, id=None, Name=None, Related_Identities=None):
         self.id = _cast(None, id)
         self.Name = Name
         self.Related_Identities = Related_Identities
-        self.xsi_type = None
     def factory(*args_, **kwargs_):
         if IdentityType.subclass:
             return IdentityType.subclass(*args_, **kwargs_)