Yaml: read and parse files thread-safe (#2188)

soda/core/soda/common/yaml_helper.py

@@ -1,29 +1,29 @@
 from ruamel.yaml import YAML, StringIO
 
 
-def create_yaml() -> YAML:
-    yaml = YAML()
-    yaml.preserve_quotes = True
-    yaml.indent(mapping=2, sequence=4, offset=2)
-    return yaml
-
-
 # Deprecated.  Replace all usages with YamlHelper.to_yaml below
 def to_yaml_str(yaml_object) -> str:
     return YamlHelper.to_yaml(yaml_object)
 
 
 class YamlHelper:
-    __yaml = create_yaml()
+    @staticmethod
+    def create_yaml() -> YAML:
+        yaml = YAML()
+        yaml.preserve_quotes = True
+        yaml.indent(mapping=2, sequence=4, offset=2)
+        return yaml
 
     @classmethod
     def to_yaml(cls, yaml_object) -> str:
         if yaml_object is None:
             return ""
         stream = StringIO()
-        cls.__yaml.dump(yaml_object, stream)
+        yaml = cls.create_yaml()  # Create a new YAML instance for thread safety
+        yaml.dump(yaml_object, stream)
         return stream.getvalue()
 
     @classmethod
     def from_yaml(cls, yaml_str) -> object:
-        return cls.__yaml.load(yaml_str)
+        yaml = cls.create_yaml()  # Create a new YAML instance for thread safety
+        return yaml.load(yaml_str)