`textInputMode` is not working on iOS 13.0 to iOS 13.3.

TextView.swift

final class TextView: UITextView {
    private var preferredTextInputModePrimaryLanguage: String?

    /**
     Use given primary language for the preferred text input mode when next time text view becomes first responder.
     - Parameters:
        - primaryLanguage: `String` represents a primary language for the preferred text input mode. Use `"emoji"` to use Emoji keyboard.
     */
    func usePreferredTextInputModePrimaryLanguage(_ primaryLanguage: String) {
        preferredTextInputModePrimaryLanguage = primaryLanguage
    }

    /**
     # UIKit Bug Workaround

     - Confirmed on iOS 13.0 to iOS 13.3.
     - Fixed on iOS 13.4.

     `textInputMode` override is completely ignored on these version of iOS 13 due to bug in `-[UIKeyboardImpl recomputeActiveInputModesWithExtensions:allowNonLinguisticInputModes:]`,
     which has a flipped condition check, which doesn't always call `-[UIKeyboardImpl setInputMode:userInitiated:]`.
     To workaround this behavior, return non `nil` identifier from `textInputContextIdentifier` to call `-[UIKeyboardImpl setInputMode:userInitiated:]` from
     `-[UIKeyboardInputModeController _trackInputModeIfNecessary:]` and bypass `-[UIKeyboardImpl recomputeActiveInputModesWithExtensions:allowNonLinguisticInputModes:]` call.
     Also need to clean up text input context identifier once it’s used for the bug workaround.

     - See also:
       - `becomeFirstResponder()`
       - `textInputContextIdentifier`
       - `textInputMode`
     */
    private let shouldWorkaroundTextInputModeBug: Bool = {
        // iOS 13.0 to iOS 13.3
        if #available(iOS 13.0, *) {
            if #available(iOS 13.4, *) {
                return false
            } else {
                return true
            }
        }
        return false
    }()

    private let preferredTextInputModeContextIdentifier = ".preferredTextInputModeContextIdentifier"

    override func becomeFirstResponder() -> Bool {
        let result = super.becomeFirstResponder()
        if result {
            if shouldWorkaroundTextInputModeBug {
                UIResponder.clearTextInputContextIdentifier(preferredTextInputModeContextIdentifier)
            }
            preferredTextInputModePrimaryLanguage = nil
        }
        return result
    }

    override var textInputContextIdentifier: String? {
        if shouldWorkaroundTextInputModeBug, preferredTextInputModePrimaryLanguage != nil {
            return preferredTextInputModeContextIdentifier
        }

        return super.textInputContextIdentifier
    }

    override var textInputMode: UITextInputMode? {
        if let preferredTextInputModePrimaryLanguage = preferredTextInputModePrimaryLanguage,
            let inputMode = UITextInputMode.activeInputModes.first(where: { $0.primaryLanguage == preferredTextInputModePrimaryLanguage }) {
            return inputMode
        }

        return super.textInputMode
    }
}