YamlReference-0.9.3: tests/l+block-mapping.n=2.invalid.output
# B: 0, C: 0, L: 1, c: 0 M # B: 0, C: 0, L: 1, c: 0 - # B: 2, C: 2, L: 1, c: 2 m # B: 2, C: 2, L: 1, c: 2 !Unexpected 'a'
# B: 0, C: 0, L: 1, c: 0 M # B: 0, C: 0, L: 1, c: 0 - # B: 2, C: 2, L: 1, c: 2 m # B: 2, C: 2, L: 1, c: 2 !Unexpected 'a'