code: function(extension) {
  	// If transformer already cached return that.
  	if (extension in transformers) {
  		return transformers[extension];
  	}
  	
  	// Retrieve the transformer if available.
  	const transformer = totransformer(extension);
  	transformers[extension] = transformer ? jstransformer(transformer) : false;
  	
  	// Return transformer.
  	return transformers[extension];
  }
docs: Matches the extension to the transformer.
  @param {String} extension The file extension.