Understanding scanned results

[arbyruns]

I'm trying to understand how periphery came to determine the following was dead code. This could also be a misunderstanding on my part, so please let me know.

scan result

0.01ms	/Volumes/macdev/fooApp/Foundations/FoundationExtensionsKit/Utilities/UnfairLock.swift:8:25	getter FoundationExtensionsKit.(file).UnfairLock._@/Volumes/macdev/fooApp/Foundations/FoundationExtensionsKit/Utilities/UnfairLock.swift:8:25

0.20ms	/Volumes/macdev/fooApp/Foundations/FoundationExtensionsKit/Utilities/UnfairLock.swift:38:26	instance method FoundationExtensionsKit.(file).UnfairLock.lock()@/Volumes/macdev/fooApp/Foundations/FoundationExtensionsKit/Utilities/UnfairLock.swift:38:26

Here's the code that was determined to not being used, but I know the lock implementation is being used within the codebase.

public final class UnfairLock: Locking {
  @usableFromInline let lockImplementation: Locking

  public init() {
    if Self.isOSAllocatedUnfairLockEnabled {
      self.lockImplementation = OSAllocatedUnfairLockWrapper()
    }
    else {
      self.lockImplementation = UnfairLockWrapper()
    }
  }

  @inlinable public func lock() {
    lockImplementation.lock()
  }
...
}