docs: def add_layer_from_yaml_file(self, filename):
          """This function implements loading a YAML file and populating a new
          empty layer (Layer) with its contents
  
          :param filename: The name of a file to read
          :type filename: string
          """
          if filename.endswith(('.yaml', '.yml')):
              file_stream = None
              try:
                  file_stream = open(os.path.abspath(filename), 'r')
                  stack = yaml.safe_load(file_stream)
  
                  self.add_layer()
                  for attribute in stack:
                      setattr(self, attribute, stack[attribute])
                  del stack
              except (TypeError, IOError):
                  logging.info("Could not import stack from %s" % filename)
              finally:
                  if file_stream:
                      file_stream.close()