public function addMapping($attributeName, $mappings)
    {
        if (!is_array($mappings)) {
            $mappings = [$mappings];
        }
        if (!$this->hasMapping($attributeName)) {
            $this->mappingsContainer[$attributeName] = [];
        }
        if ($this->mappingsContainer[$attributeName] !== null) {
            foreach ($mappings as $mapping) {
                $this->mappingsContainer[$attributeName][] = $mapping;
            }
        }
        return $this;
    }