         XCTAssertNotNil(inputStream.availablePhysicalFormatsMatchingCurrentNominalSampleRate(true))
         XCTAssertNotNil(inputStream.availablePhysicalFormatsMatchingCurrentNominalSampleRate(false))
 
-        let inVirtualFormat = try XCTUnwrap(inputStream.availableVirtualFormatsMatchingCurrentNominalSampleRate()?.first)
         inputStream.virtualFormat = nil
-        XCTAssertEqual(inputStream.virtualFormat, inVirtualFormat)
+        XCTAssertNotNil(inputStream.virtualFormat)
 
-        let inPhysicalFormat = try XCTUnwrap(inputStream.availablePhysicalFormatsMatchingCurrentNominalSampleRate()?.first)
         inputStream.physicalFormat = nil
-        XCTAssertEqual(inputStream.physicalFormat, inPhysicalFormat)
+        XCTAssertNotNil(inputStream.physicalFormat)
     }
 
     // MARK: - Private Functions

        XCTAssertNotNil(outputStream.availablePhysicalFormatsMatchingCurrentNominalSampleRate(true))
        XCTAssertNotNil(outputStream.availablePhysicalFormatsMatchingCurrentNominalSampleRate(false))

        let outVirtualFormat = try XCTUnwrap(outputStream.availableVirtualFormatsMatchingCurrentNominalSampleRate()?.first)
        outputStream.virtualFormat = nil
        XCTAssertEqual(outputStream.virtualFormat, outVirtualFormat)

        let outPhysicalFormat = try XCTUnwrap(outputStream.availablePhysicalFormatsMatchingCurrentNominalSampleRate()?.first)
        outputStream.physicalFormat = nil
        XCTAssertEqual(outputStream.physicalFormat, outPhysicalFormat)

        let inputStream = try XCTUnwrap(inputStreams.first)
        XCTAssertTrue(inputStream.active)

import XCTest
@testable import AMCoreAudio

class AudioStreamTests: XCTestCase {
    func testProperties() throws {
