relation completer progress

source/core/object/relation_endpoint.cpp

@@ -18,4 +18,16 @@ relation_type relation_endpoint::type() const {
 const schema_node &relation_endpoint::node() const {
   return *node_;
 }
-}
+
+bool relation_endpoint::is_has_one() const {
+  return type_ == relation_type::HAS_ONE;
+}
+
+bool relation_endpoint::is_has_many() const {
+  return type_ == relation_type::HAS_MANY;
+}
+
+bool relation_endpoint::is_belongs_to() const {
+  return type_ == relation_type::BELONGS_TO;
+}
+}