for 循环修改 model.Schema 实体的某个属性值（这个属性是一个索引，不可重复），批量插入数据库

Question

在写demo的时候，我需要使用for循环修改一个model实体的索引的值，伪造数据批量插入Collection。
varepsonl_1=newEpsonl({
NAME:'',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
size:0
});
这里的Epsonl是modelSchema，那么epsonl_1就是这个Schema的一个实体对吧？我现在需要修改这个实体的NAME属性的值，我使用for循环修改，代码：
for(leti=0;i<50;i++){
epsonl_1.NAME='test'+i;
console.log(epsonl_1.NAME);
docs.push(epsonl_1);
}
使用一个docs数组保存修改后的实体
vardocs=[];
然后，我启动程序，发现数据库只插入了一条文档，并且他的NAME属性的值为test49，而我在for循环内部使用console.log(epsonl_1.NAME);查看时，发现
test0
test1
test2
test3
test4
test5
test6
test7
test8
test9
test10
test11
test12
test13
test14
test15
test16
test17
test18
test19
test20
test21
test22
test23
test24
test25
test26
test27
test28
test29
test30
test31
test32
test33
test34
test35
test36
test37
test38
test39
test40
test41
test42
test43
test44
test45
test46
test47
test48
test49
于是我又输出了数组docs的值：
[{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635},
{NAME:'test49',
CONTENT:false,
NUMBER:12,
DIRECTION:false,
COLOR:false,
PATH:'c:\file.docx',
_id:59758b259117550bb4fdd635}]
...
NAME属性的值全部都是test49，这样我就晕了。请问各位大佬怎么解决这个问题，顺便麻烦解释一下其中的原因。
插入到集合只有一个文档，这我理解，NAME属性的值不可重复。