private function existingPropertyGetterAvailableOrFail(string $propertyName): void
    {
        assert($this->propertyExists($propertyName));
        if (!$this->isExistingPropertyGetterAvailable($propertyName)) {
            throw new UnavailableOperationException($propertyName);
        }
    }
private function existingPropertyGetterAvailableOrFail(string $propertyName): void
    {
        assert($this->propertyExists($propertyName));
        if (!$this->isExistingPropertyGetterAvailable($propertyName)) {
            throw new UnavailableOperationException($propertyName);
        }
    }
private function existingPropertyGetterAvailableOrFail ( string $ propertyName ) : void { assert ( $ this -> propertyExists ( $ propertyName ) ) ; if ( ! $ this -> isExistingPropertyGetterAvailable ( $ propertyName ) ) { throw new UnavailableOperationException ( $ propertyName ) ; } }
Fail if the getter of an existing property is not available.

@param string $propertyName
@return bool

@throws UnavailableOperationException
Fail if the getter of an existing property is not available .