JSONファイルの共通の属性名について

for文で3つのjsonファイルの中身を出したのですが、以下のjsonファイルの共通の属性名を教えていただけないでしょうか？

python
1for i in range(3):
2    print('Line {}'.format(i+1))
3    print(augmented_manifest_lines[i])
4    print('\n')
5>>>>>>
6
7Preview of Augmented Manifest File Contents
8-------------------------------------------
9
10Line 1
11{"source-ref":"s3://sagemaker-segment/semantic/training/19_002400.png","semantic-test-ref":"s3://sagemaker-segment/semantic/train-ano/semantic-test/annotations/consolidated-annotation/output/0_2019-09-08T04:27:08.306525.png","semantic-test-ref-metadata":{"job-name":"labeling-job/semantic-test","type":"groundtruth/semantic-segmentation","creation-date":"2019-09-08T04:27:08.412696","internal-color-map":{"0":{"confidence":0.79862,"class-name":"BACKGROUND"},"1":{"confidence":0.79862,"class-name":"car"},"2":{"confidence":0.79862,"class-name":"person"}},"human-annotated":"yes"}}
12
13
14Line 2
15{"source-ref":"s3://sagemaker-segment/semantic/training/19_002600.png","semantic-test-ref":"s3://sagemaker-segment/semantic/train-ano/semantic-test/annotations/consolidated-annotation/output/1_2019-09-08T04:32:57.767576.png","semantic-test-ref-metadata":{"job-name":"labeling-job/semantic-test","type":"groundtruth/semantic-segmentation","creation-date":"2019-09-08T04:32:57.834311","internal-color-map":{"0":{"confidence":0.7423700000000001,"class-name":"BACKGROUND"},"1":{"confidence":0.7423700000000001,"class-name":"car"},"2":{"confidence":0.7423700000000001,"class-name":"person"}},"human-annotated":"yes"}}
16
17
18Line 3
19{"source-ref":"s3://sagemaker-segment/semantic/training/19_003800.png","semantic-test-ref":"s3://sagemaker-segment/semantic/train-ano/semantic-test/annotations/consolidated-annotation/output/2_2019-09-08T04:34:07.804037.png","semantic-test-ref-metadata":{"job-name":"labeling-job/semantic-test","type":"groundtruth/semantic-segmentation","creation-date":"2019-09-08T04:34:07.880066","internal-color-map":{"0":{"confidence":0.7699100000000001,"class-name":"BACKGROUND"},"1":{"confidence":0.7699100000000001,"class-name":"car"},"2":{"confidence":0.7699100000000001,"class-name":"person"}},"human-annotated":"yes"}}
20