# File lib/jmespath/nodes/function.rb, line 103
      def call(args)
        if args.count == 1
          values = args.first
        else
          return maybe_raise Errors::InvalidArityError, "function avg() expects one argument"
        end
        if Array === values
          return nil if values.empty?
          values.inject(0) do |total,n|
            if Numeric === n
              total + n
            else
              return maybe_raise Errors::InvalidTypeError, "function avg() expects numeric values"
            end
          end / values.size.to_f
        else
          return maybe_raise Errors::InvalidTypeError, "function avg() expects a number"
        end
      end