From 00462eb683cf519eb5fe90b2bfe7093b5cd9fd1e Mon Sep 17 00:00:00 2001
From: Emmanuelle Vargas-Gonzalez <emmanuelle@mitre.org>
Date: Mon, 14 Aug 2017 14:37:49 -0400
Subject: [PATCH] Add hashes property to ExternalReference, more documentation
 for parse_observable

---
 stix2/observables.py | 10 ++++++----
 stix2/other.py       |  7 ++++---
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/stix2/observables.py b/stix2/observables.py
index 5e1bbf8..87f95e2 100644
--- a/stix2/observables.py
+++ b/stix2/observables.py
@@ -734,17 +734,19 @@ EXT_MAP = {
     'network-traffic': EXT_MAP_NETWORK_TRAFFIC,
     'process': EXT_MAP_PROCESS,
     'user-account': EXT_MAP_USER_ACCOUNT,
-
 }
 
 
 def parse_observable(data, _valid_refs, allow_custom=False):
-    """Deserialize a string or file-like object into a STIX Cyber Observable object.
+    """Deserialize a string or file-like object into a STIX Cyber Observable
+    object.
 
     Args:
         data: The STIX 2 string to be parsed.
-        _valid_refs: A list of object references valid for the scope of the object being parsed.
-        allow_custom: Whether to allow custom properties or not. Default: False.
+        _valid_refs: A list of object references valid for the scope of the
+            object being parsed. Use empty list if no valid refs are present.
+        allow_custom: Whether to allow custom properties or not.
+            Default: False.
 
     Returns:
         An instantiated Python STIX Cyber Observable object.
diff --git a/stix2/other.py b/stix2/other.py
index b2492c4..9659dca 100644
--- a/stix2/other.py
+++ b/stix2/other.py
@@ -3,9 +3,9 @@
 from collections import OrderedDict
 
 from .base import _STIXBase
-from .properties import (IDProperty, ListProperty, Property, ReferenceProperty,
-                         SelectorProperty, StringProperty, TimestampProperty,
-                         TypeProperty)
+from .properties import (IDProperty, HashesProperty, ListProperty, Property,
+                         ReferenceProperty, SelectorProperty, StringProperty,
+                         TimestampProperty, TypeProperty)
 from .utils import NOW, get_dict
 
 
@@ -15,6 +15,7 @@ class ExternalReference(_STIXBase):
         ('source_name', StringProperty(required=True)),
         ('description', StringProperty()),
         ('url', StringProperty()),
+        ('hashes', HashesProperty()),
         ('external_id', StringProperty()),
     ])