def options=(options)
      fail ArgumentError, 'options must be a Hash. ' \
                          "#{ options.inspect } given." unless options.is_a?(Hash)

      @options.merge! options

      build_query
    end
def options=(options)
      fail ArgumentError, 'options must be a Hash. ' \
                          "#{ options.inspect } given." unless options.is_a?(Hash)

      @options.merge! options

      build_query
    end
Change search options with a hash, triggering a query string rebuild and
 clearing past results.

 Raises ArgumentError if options is not a Hash