code: def derive_child_context(self, whence):
          
          return _HandlerContext(
              container=self.container,
              queue=self.queue,
              field_name=None,
              annotations=None,
              depth=self.depth,
              whence=whence,
              value=bytearray(),  # children start without a value
              ion_type=None,
              pending_symbol=None
          )
docs: Derives a scalar context as a child of the current context.