How to use UnsafeMutablePointer<OpaquePointer> in Swift?

How does one use an UnsafeMutablePointer<OpaquePointer> in Swift with some Core Foundation framework? Why have an UnsafeMutablePointer<OpaquePointer>?

Given, general: some UnsafeMutablePointer<SomeType> where typealias SomeType = OpaquePointer

Specific Example API

// SOURCE: import ApplicationServices.PrintCore
typealias PMPrinter = OpaquePointer
func PMSessionGetCurrentPrinter(_ printSession: PMPrintSession, _ currentPrinter: UnsafeMutablePointer<PMPrinter>)
func PMPrinterGetPaperList(PMPrinter, UnsafeMutablePointer<Unmanaged<CFArray>?>)

Specific Example Use Case: get list of papers supported by a printer

let printInfo = NSPrintInfo.shared()
let printSession = PMPrintSession(printInfo.pmPrintSession())
var currentPrinterOptional: PMPrinter? = nil
PMSessionGetCurrentPrinter(printSession, &currentPrinterOptional!)
guard let currentPrinter = currentPrinterOptional else { return }

// Get the array of pre-defined PMPapers this printer supports.
// PMPrinterGetPaperList(PMPrinter, UnsafeMutablePointer<Unmanaged<CFArray>?>)
var paperListUnmanaged: Unmanaged<CFArray>?
PMPrinterGetPaperList(currentPrinter, &paperListUnmanaged)
guard let paperList = paperListUnmanaged?.takeUnretainedValue() as [AnyObject]? else { return }

Observed Errors

What compiles does not run. What seems like (maybe) reasonable syntax does not compile.

The above example gets the following (expected) Runtime "fatal error: unexpectedly found nil while unwrapping an Optional value".

Some select other attempts:

// Compile Error: Address of variable 'currentPrinter' taken before is is initialized
var currentPrinter: PMPrinter
PMSessionGetCurrentPrinter(printSession, &currentPrinter)

// Compile Error: Nil cannot initialze specified type 'PMPrinter' (aka 'OpaquePointer')
var currentPrinter: PMPrinter = nil
PMSessionGetCurrentPrinter(printSession, &currentPrinter)

// Compile Error: Variable 'currentPrinterPtr' used before being initialized
var currentPrinterPtr: UnsafeMutablePointer<PMPrinter>
PMSessionGetCurrentPrinter(printSession, currentPrinterPtr)

// Compile OK: actually compiles
// Runtime Error: unexpectedly found nil while unwrapping an Optional value
var currentPrinterOptional: PMPrinter? = nil
PMSessionGetCurrentPrinter(printSession, &currentPrinterOptional!)

Resources

Apple: Core Printing ⇗
Apple: Using Swift with Cocoa and Objective-C ⇗

While the docs have useful information, a workable implementation for UnsafeMutablePointer<PMPrinter> with typealias as UnsafeMutablePointer<OpaquePointer> has been elusive.