lib/semantic_logger/base.rb
def push_tags(*tags)
      # Need to flatten and reject empties to support calls from Rails 4
      new_tags = tags.flatten.collect(&:to_s).reject(&:empty?)
      SemanticLogger.push_tags(*new_tags)
    end
def push_tags(*tags)
      # Need to flatten and reject empties to support calls from Rails 4
      new_tags = tags.flatten.collect(&:to_s).reject(&:empty?)
      SemanticLogger.push_tags(*new_tags)
    end
Returns the list of tags pushed after flattening them out and removing blanks

 Note:
 - This method is slow since it needs to flatten the tags and remove empty elements
   to support Rails 4.
 - For better performance with clean tags, use `SemanticLogger.push_tags`