func (i Info) AvailFrac() float64 {
	return float64(i.Available()) / float64(i["MemTotal"])
}
AvailFrac returns the available memory as a fraction of total.
package meminfo  
import (
	"bufio"
	"strconv"
	"strings"
	"sync"
	"time"
	"barista.run/bar"
	"barista.run/base/value"
	"barista.run/format"
	l "barista.run/logging"
	"barista.run/outputs"
	"barista.run/timing"
	"github.com/martinlindhe/unit"
	"github.com/spf13/afero"
)
type Info map[string]unit.Datasize
func (i Info) FreeFrac(k string) float64 {
	return float64(i[k+"Free"]) / float64(i[k+"Total"])
}
func (i Info) Available() unit.Datasize {
	if avail, ok := i["MemAvailable"]; ok {
		return avail
	}
	return i["MemFree"] + i["Cached"] + i["Buffers"]
}