func (tsr *Int64) SetNull(i []int, nul bool) {
	if tsr.Nulls == nil {
		tsr.Nulls = bitslice.Make(tsr.Len(), 0)
	}
	j := tsr.Offset(i)
	tsr.Nulls.Set(j, nul)
}
SetNull sets whether given index has a null value or not.
All values are assumed valid (non-Null) until marked otherwise, and calling
this method creates a Null bitslice map if one has not already been set yet.
package etensor
import (
	"errors"
	"fmt"
	"log"
	"math"
	"strconv"
	"strings"
	"github.com/apache/arrow/go/arrow"
	"github.com/apache/arrow/go/arrow/array"
	"github.com/apache/arrow/go/arrow/memory"
	"github.com/apache/arrow/go/arrow/tensor"
	"github.com/emer/etable/bitslice"
	"github.com/goki/ki/ints"
	"github.com/goki/ki/kit"
	"gonum.org/v1/gonum/mat"
)
type Int64 struct {
	Shape
	Values []int64
	Nulls  bitslice.Slice
	Meta   map[string]string
}
func NewInt64(shape, strides []int, names []string) *Int64 {
	tsr := &Int64{}
	tsr.SetShape(shape, strides, names)
	tsr.Values = make([]int64, tsr.Len())
	return tsr
}
func NewInt64Shape(shape *Shape, vals []int64) *Int64 {
	tsr := &Int64{}
	tsr.CopyShape(shape)
	if vals != nil {
		if len(vals) != tsr.Len() {
			log.Printf("etensor.New*Shape: length of provided vals: %d not proper length: %d", len(vals), tsr.Len())
			tsr.Values = make([]int64, tsr.Len())
		} else {
			tsr.Values = vals
		}
	} else {
		tsr.Values = make([]int64, tsr.Len())
	}
	return tsr
}
func (tsr *Int64) ShapeObj() *Shape       { return &tsr.Shape }
func (tsr *Int64) DataType() Type         { return INT64 }
func (tsr *Int64) Value(i []int) int64    { j := tsr.Offset(i); return tsr.Values[j] }
func (tsr *Int64) Value1D(i int) int64    { return tsr.Values[i] }
func (tsr *Int64) Set(i []int, val int64) { j := tsr.Offset(i); tsr.Values[j] = val }
func (tsr *Int64) Set1D(i int, val int64) { tsr.Values[i] = val }
func (tsr *Int64) IsNull(i []int) bool {
	if tsr.Nulls == nil {
		return false
	}
	j := tsr.Offset(i)
	return tsr.Nulls.Index(j)
}
func (tsr *Int64) IsNull1D(i int) bool {
	if tsr.Nulls == nil {
		return false
	}
	return tsr.Nulls.Index(i)
}