func NewMemFileWriter(name string, f OnCloseFunc) (source.ParquetFile, error) {
	if memFs == nil {
		memFs = afero.NewMemMapFs()
	}
	var m MemFile
	m.OnClose = f
	return m.Create(name)
}
NewMemFileWriter - intiates and creates an instance of MemFiles
NOTE: there is no NewMemFileReader as this particular type was written
to handle in-memory conversions and offloading. The results of
conversion can then be stored and read via HDFS, LocalFS, etc without
the need for loading the file back into memory directly
package mem
import (
	"io"
	"path/filepath"
	"github.com/spf13/afero"
	"github.com/xitongsys/parquet-go/source"
)
var memFs afero.Fs
func SetInMemFileFs(fs *afero.Fs) {
	memFs = *fs
}
func GetMemFileFs() afero.Fs {
	return memFs
}
type OnCloseFunc func(string, io.Reader) error
type MemFile struct {
	FilePath string
	File     afero.File
	OnClose  OnCloseFunc
}