src/Eager.php
public function save($id, $content, $lifeTime = 0)
    {
        if (is_object($content)) {
            throw new \InvalidArgumentException('You cannot use this cache to cache an object, only arrays, strings and numbers. Have a look at Transient cache.');
            // for performance reasons we do currently not recursively search whether any array contains an object.
        }

        $this->content[$id] = $content;
        $this->isDirty = true;
        return true;
    }
public function save($id, $content, $lifeTime = 0)
    {
        if (is_object($content)) {
            throw new \InvalidArgumentException('You cannot use this cache to cache an object, only arrays, strings and numbers. Have a look at Transient cache.');
            // for performance reasons we do currently not recursively search whether any array contains an object.
        }

        $this->content[$id] = $content;
        $this->isDirty = true;
        return true;
    }
Puts data into the cache.

@param string $id The cache id.
@param int|float|string|boolean|array $content
@param int $lifeTime Setting a lifetime is not supported by this cache and the parameter will be ignored.
@return boolean