#实际值为 something \n something
str: "something \n something"
#实际值为 something 换行 something
str: 'something \n something'
#实际值为 line1 line2 line3
str: line1
line2
line3
#实际值为 line1换行line2换行line3换行
str: |
line1
line2
line3
#实际值为 line1换行line2换行line3换行换行换行
str: |+
line1
line2
line3
other: ...
#实际值为 line1换行line2换行line3
str: |-
line1
line2
line3
other: ...