Access Token for non-Microsoft Graph API

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### This issue is for a: (mark with an `x`)
```
- [ ] bug report -> please search issues before submitting
- [ ] feature request
- [ X] documentation issue or request
- [ ] regression (a behavior that used to work and stopped in a new release)
```

### Minimal steps to reproduce
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### Any log messages given by the failure
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### Expected/desired behavior
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### OS and Version?
> Windows 7, 8 or 10. Linux (which distribution). macOS (Yosemite? El Capitan? Sierra?)

### Versions
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### Mention any other details that might be useful
I am trying to access an API on the same server that my android app is registered. The process of logging into the android app works fine. I have attempted to use the IAuthenticationResult.getAccessToken() generated to access an API on the same server as a bearer token unsuccessfully. I get a 401 Unauthorized error message both on Postman and my application. The sample applications available including this one work fine with Microsoft Graph but I haven't seen any sample accessing other forms of API including end points hosted in the same client.
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