def check_plugins(config)
      if config.key?("plugins") && config["plugins"].is_a?(String)
        Jekyll.logger.error "Configuration Error:", "You specified the" \
          " `plugins` config in your configuration file as a string, please" \
          " use an array instead. If you wanted to set the directory of your" \
          " plugins, use the config key `plugins_dir` instead."
        raise Jekyll::Errors::InvalidConfigurationError,
              "'plugins' should not be a string, but was: " \
              "#{config["plugins"].inspect}. Use 'plugins_dir' instead."
      end
    end
def check_plugins(config)
      if config.key?("plugins") && config["plugins"].is_a?(String)
        Jekyll.logger.error "Configuration Error:", "You specified the" \
          " `plugins` config in your configuration file as a string, please" \
          " use an array instead. If you wanted to set the directory of your" \
          " plugins, use the config key `plugins_dir` instead."
        raise Jekyll::Errors::InvalidConfigurationError,
              "'plugins' should not be a string, but was: " \
              "#{config["plugins"].inspect}. Use 'plugins_dir' instead."
      end
    end
Private: Checks if the `plugins` config is a String

 config - the config hash

 Raises a Jekyll::Errors::InvalidConfigurationError if the config `plugins`
 is a string