code: def get_attribute(self, attribute: str) -> 'Node':
          
          matches = [
              value_node for key_node, value_node in self.yaml_node.value
              if key_node.value == attribute
          ]
          if len(matches) != 1:
              raise SeasoningError(
                  'Attribute not found, or found multiple times: {}'.format(
                      matches))
          return Node(matches[0])
docs: Returns the node representing the given attribute's value.
  
          Use only if is_mapping() returns true.
  
          Args:
              attribute: The name of the attribute to retrieve.
  
          Raises:
              KeyError: If the attribute does not exist.
  
          Returns:
              A node representing the value.