How to use the klein.Field.password function in klein

    password=Field.password(),
)
@inlineCallbacks
def doSignup(username, email, password, binding):
    # type: (str, str, str, ISimpleAccountBinding) -> Deferred
    acct = yield binding.createAccount(username, email, password)
    result = {
        "signupActive": "active",
        "accountID": None
    }
    if acct is None:
        result.update({
            "success": "Account creation failed!",
            "link_message": "try again",
            "next_url": "/signup",
        })
    else: