public function getActivationConditionTreeForField(Field $field)
    {
        $key = $field->getName();

        if (false === array_key_exists($key, $this->fieldsTrees)) {
            $this->fieldsTrees[$key] = $this->getConditionTree($field->getActivation());
        }

        $this->fieldsTrees[$key]->injectDependencies($this, $field->getActivation());

        return $this->fieldsTrees[$key];
    }