def functions
      @functions ||= @api_info.fetch("functions").inject({}) do |acc, func|
        function = Function.new(func)
        acc.merge(function.name => function)
      end
    end
def functions
      @functions ||= @api_info.fetch("functions").inject({}) do |acc, func|
        function = Function.new(func)
        acc.merge(function.name => function)
      end
    end
Return all functions defined by the API.