code: def add_metadata(self, namespace, name, value, others=None):
          "Add metadata"
  
          if namespace in NAMESPACES:
              namespace = NAMESPACES[namespace]
  
          if namespace not in self.metadata:
              self.metadata[namespace] = {}
  
          if name not in self.metadata[namespace]:
              self.metadata[namespace][name] = []
  
          self.metadata[namespace][name].append((value, others)f add_metadata(self, namespace, name, value, others=None):
          "Add metadata"
  
          if namespace in NAMESPACES:
              namespace = NAMESPACES[namespace]
  
          if namespace not in self.metadata:
              self.metadata[namespace] = {}
  
          if name not in self.metadata[namespace]:
              self.metadata[namespace][name] = []
  
          self.metadata[namespace][name].append((value, others))
docs: Add metadata