@staticmethod
def mapping_layer():
    ' 获取符号映射关系.\n        Returns:\n            layer: 符号映射关系\n        '
    return None
获取符号映射关系.
Returns:
    layer: 符号映射关系
@staticmethod
def mapping_layer():
    ' 获取符号映射关系.\n        Returns:\n            layer: 符号映射关系\n        '
    return None