Elasticsearch index not_analyzed

I have a data, example:
a b
this data beginning with multiple spaces and more than one space between this data.
My mapping set no_analyzed, save this data to es,when search this data,This data has only one space, example:
a b
I don't know why this is.

Can you provide us with a recreation of the bug? For instance using curl commands.

1.curl -XPOST '' -d '{
"mappings": {
"post": {
"properties": {
"msg": {
"type": "string",
"index": "not_analyzed",
"store": "yes"

2.curl -XPUT -d '{"msg": " a b"}'

3.I use elasticsearch web ui Any Request perform a search command {"query":{"match_all":{}}},give me return result is " a b".I think that it is " a b". Why space is gone?There are multiple spaces between a and b, but query results and only one space.

What happens if you run a curl command to search?

What is "elastsearch web UI"?

My original data has multiple consecutive spaces, but I looked at the results of only a single space .
elasticsearch web UI is port 9200.
I found ths problem, browser parsed consecutive spaces to one space.