keras/src/models/sequential.py/Sequential/__init__
class Sequential:    def __init__(self, layers=None, trainable=True, name=None):
        super().__init__(trainable=trainable, name=name)
        self._functional = None
        self._layers = []
        if layers:
            for layer in layers:
                self.add(layer, rebuild=False)
            self._maybe_rebuild()