我在同一页面上有一个MdDialog和MdSnakBar的网页。在此页面上显示MdSnackBar会出错：
OverlayState is not a constructor at MdSnackBar._createOverlay
Error: Uncaught (in promise): TypeError:
__WEBPACK_IMPORTED_MODULE_5__angular_cdk_overlay__.OverlayState is not a constructor
TypeError: __WEBPACK_IMPORTED_MODULE_5__angular_cdk_overlay__.OverlayState is
not a constructor
at MdSnackBar._createOverlay
我如何解决这个问题？
Package.json dep版本：
"@angular/animations": "4.3.5",
"@angular/cdk": "2.0.0-beta.10",
"@angular/common": "4.3.5",
"@angular/compiler": "4.3.5",
"@angular/compiler-cli": "4.3.5",
"@angular/core": "4.3.5"