Function guard

guard(ptr, usecases, destinations?, onPass?, onFail?, origin?): boolean
Guard against an invalid LicenseRecord for a list of usecases and destinations.

Use this method to verify that a non-expired LicenseRecord for the specified pointer record exists and permits the listed usecases and destinations.

This method can be used in two ways:
1. As an async traditional guard, returning a pass/fail boolean:
```
const pass: boolean = await TikiSdk.guard("example-ptr", [TikiSdk.LicenseUsecase.attribution], ["https://example.com"]);
if (pass) {
  // Perform the action allowed by the LicenseRecord.
}
```
1. As a wrapper around a function:
```
TikiSdk.guard("example-ptr", [TikiSdk.LicenseUsecase.attribution], destinations: ["https://example.com"],
() => {
  // Perform the action allowed by the LicenseRecord.
},
(reason) => {
  // Handle the error.
});
```
Parameters
- ptr: string
  
  The pointer record for the asset. Used to locate the latest relevant LicenseRecord.
- usecases: LicenseUsecase[]
  
  A list of usecases defining how the asset will be used.
- Optional destinations: string[]
  
  A list of destinations defining where the asset will be used, often URLs.
- Optional onPass: (() => void)
  
  A closure to execute automatically upon successfully resolving the LicenseRecord against the usecases and destinations.
  - - (): void
    - Returns void
- Optional onFail: ((reason) => void)
  
  A closure to execute automatically upon failure to resolve the LicenseRecord. Accepts an optional error message describing the reason for failure.
  - - (reason): void
    - Parameters
      
      reason: string
      
      Returns void
- Optional origin: string
  
  An optional override of the default origin specified in initialize.
Returns boolean
- Defined in trail/trail.ts:65