# File lib/selenium/webdriver/remote/capabilities.rb, line 187
        def merge!(other)
          if other.respond_to?(:capabilities) && other.capabilities.kind_of?(Hash)
            @capabilities.merge! other.capabilities
          elsif other.kind_of? Hash
            @capabilities.merge! other
          else
            raise ArgumentError, "argument should be a Hash or implement #capabilities"
          end
        end