requestPermission abstract method
Request permission to access the location of the device.
Returns a Future which when completes indicates if the user granted
permission to access the device's location.
Throws a PermissionDefinitionsNotFoundException
when the required
platform specific configuration is missing (e.g. in the
AndroidManifest.xml on Android or the Info.plist on iOS).
A PermissionRequestInProgressException
is thrown if permissions are
requested while an earlier request has not yet been completed.
Implementation
Future<LocationPermission> requestPermission();