code: public function setMappings($mappingName, array $mappingConfig = null)
  	{
  		if (is_array($mappingName) === false)
  		{
  			$mappingName = array($mappingName => $mappingConfig);
  		}
  
  		\Arr::set($this->config['mappings'], $mappingName);
  
  		return $this;
  	}
docs: Sets a mapping configuration
  
  @param string $mappingName
  @param array  $mappingConfig
  
  @return this