YAML file: a.yml
  YAML document
    YAML sequence
      YAML sequence item
        PsiElement(-)('-')
        PsiElement(Eol)('\n')
        PsiElement(indent)('  ')
        YAML mapping
          YAML key value
            PsiElement(scalar key)('name')
            PsiElement(:)(':')
            PsiWhiteSpace(' ')
            YAML plain scalar text
              PsiElement(text)('Mark McGwire')
          PsiElement(Eol)('\n')
          PsiElement(indent)('  ')
          YAML key value
            PsiElement(scalar key)('hr')
            PsiElement(:)(':')
            PsiWhiteSpace('   ')
            YAML plain scalar text
              PsiElement(text)('65')
          PsiElement(Eol)('\n')
          PsiElement(indent)('  ')
          YAML key value
            PsiElement(scalar key)('avg')
            PsiElement(:)(':')
            PsiWhiteSpace('  ')
            YAML plain scalar text
              PsiElement(text)('0.278')
      PsiElement(Eol)('\n')
      YAML sequence item
        PsiElement(-)('-')
        PsiElement(Eol)('\n')
        PsiElement(indent)('  ')
        YAML mapping
          YAML key value
            PsiElement(scalar key)('name')
            PsiElement(:)(':')
            PsiWhiteSpace(' ')
            YAML plain scalar text
              PsiElement(text)('Sammy Sosa')
          PsiElement(Eol)('\n')
          PsiElement(indent)('  ')
          YAML key value
            PsiElement(scalar key)('hr')
            PsiElement(:)(':')
            PsiWhiteSpace('   ')
            YAML plain scalar text
              PsiElement(text)('63')
          PsiElement(Eol)('\n')
          PsiElement(indent)('  ')
          YAML key value
            PsiElement(scalar key)('avg')
            PsiElement(:)(':')
            PsiWhiteSpace('  ')
            YAML plain scalar text
              PsiElement(text)('0.288')