error on AoT compilation

[fulls1z3]

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[X] bug report => check the README and search github for a similar issue or PR before submitting
[ ] support request => check the README and search github for a similar issue or PR before submitting
[ ] feature request

Current behavior
@ngx-cache/core does not compile on AoT:

Metadata collected contains an error that will be reported at runtime: Only initialized variables and constants can be referenced because the value of this variable is needed by the template compiler.

Expected/desired behavior
It should compile on AoT.

Minimal reproduction of the problem with instructions

What is the motivation / use case for changing the behavior?

Please tell us about your environment:

• Angular version: 2.0.X

• Browser: [all | Chrome XX | Firefox XX | IE XX | Safari XX | Mobile Chrome XX | Android X.X Web Browser | iOS XX Safari | iOS XX UIWebView | iOS XX WKWebView ]

• Language: [all | TypeScript X.X | ES6/7 | ES5]

• Node (for AoT issues): node --version =