If the current job is the latest one in the loader pool and the job is deleted,
the job goes into an infinite cycle of load-fail-delete-reload-load-fail-delete.
So we need to prevent the infinite loop during XAI data loading failed.

1. delete the unused code, catch unknown error is unused in explain_parser.py
2. fix bug the lastest file size is unused
3. rename some variables and fix some spelling error

Support to stop the loader that is currently loading data when add a new loader to cache by get_job method
Add the UT usecase to the stop mechanism

FIFO queue mechanism is adopted for loader cache

From: @ngtony
Reviewed-by: @wangyue01,@wenkai_dist
Signed-off-by: @wenkai_dist

fix pylint issues

From: @yuhanshi
Reviewed-by: @ouwenchang,@ouwenchang,@wenkai_dist
Signed-off-by: @wenkai_dist

From: @ngtony
Reviewed-by: @ouwenchang,@ouwenchang,@wangyue01
Signed-off-by: @wangyue01

enhance query image error message

bugfix and add pillow to requirements.txt

modify summary format

bugfix

use sample_id in summary

fix CI problem

url encode '/' as well

fix ut

fix ut

fix ut

fix uncertainty enable checking

fix review comment

enhance exception raising

enhance comment

Merge pull request !816 from TonyNG/master

Merge pull request !810 from YuhanShi/ExplainJob_v1.1

fix UT

del unused arguments

fix UT

explainer_api UT change to pytest style

fix UT url

explainer encapsulator UT change to pytest style

remove unnecessary deepcopy

remove import copy

fix some coding style issues

Merge pull request !800 from YuhanShi/ExplainJob_v1.0

Merge pull request !795 from TonyNG/master

json return null if ExplainManager returns None

use fromtimestamp

use fromtimestamp

wrong name

wrong json key

use offset as page offset

enhance comments

rm mock_explainer_api.py

update copyright year 2020

remove unused import

modification for parser

modification for parser with containers

fix bugs for parser

fix value vacancy for parser

fix typos for parser

adaptation for proto modification

rearrange image data from events

fix small typo

add comments and some error message

delete example

modify init setting of parser

modify some structure of parser

fix pylint warnings

modify parser for parsing one event every time

modify for review

add some comments

modify proto file

modify for open source comments